boot: move package options to a submenu

Change all Kconfig entries for packages in the "Bootloaders" menu to
submenus.

Currently many bootloaders and firmwares in this menu use a 'config'
keyword and thus menuconfig presents their sub-options as a flat list in
the same menu. This is not very convenient as some have a lot of
sub-options, and in (more and more common) configurations with multiple
such packages enabled the menuconfig screen becomes very crowded. Moreover
options of 'string' type don't have a visible indentation when their value
exceeds a few characters, thus making it visually hard to grasp which
package the various options belong to.

Non-bootloader packages having suboptions usually use a 'menuconfig'
keywork to have sub-options in a submenu. Do the same for packages in the
"Bootloaders" menu which have more than one sub-option.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Neal Frager <neal.frager@amd.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>

boot/afboot-stm32/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_AFBOOT_STM32
+menuconfig BR2_TARGET_AFBOOT_STM32
 	bool "afboot-stm32"
 	depends on BR2_arm
 	help

boot/arm-trusted-firmware/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_ARM_TRUSTED_FIRMWARE
+menuconfig BR2_TARGET_ARM_TRUSTED_FIRMWARE
 	bool "ARM Trusted Firmware (ATF)"
 	depends on (BR2_ARM_CPU_ARMV8A || BR2_ARM_CPU_ARMV7A)
 	help

boot/at91bootstrap3/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_AT91BOOTSTRAP3
+menuconfig BR2_TARGET_AT91BOOTSTRAP3
 	bool "AT91 Bootstrap 3+"
 	depends on BR2_arm926t || BR2_cortex_a5 || BR2_cortex_a7
 	help

boot/barebox/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_BAREBOX
+menuconfig BR2_TARGET_BAREBOX
 	bool "Barebox"
 	help
 	  The Barebox bootloader, formerly known as U-Boot v2.

boot/boot-wrapper-aarch64/Config.in

@@ -2,7 +2,7 @@ comment "boot-wrapper-aarch64 needs a Linux kernel to be built"
 	depends on BR2_aarch64
 	depends on !BR2_LINUX_KERNEL
 
-config BR2_TARGET_BOOT_WRAPPER_AARCH64
+menuconfig BR2_TARGET_BOOT_WRAPPER_AARCH64
 	bool "boot-wrapper-aarch64"
 	depends on BR2_aarch64
 	depends on BR2_LINUX_KERNEL

boot/grub2/Config.in

@@ -7,7 +7,7 @@ config BR2_TARGET_GRUB2_ARCH_SUPPORTS
 	default y if BR2_RISCV_64
 	depends on BR2_USE_MMU
 
-config BR2_TARGET_GRUB2
+menuconfig BR2_TARGET_GRUB2
 	bool "grub2"
 	depends on BR2_TARGET_GRUB2_ARCH_SUPPORTS
 	depends on BR2_USE_WCHAR

boot/mxs-bootlets/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_MXS_BOOTLETS
+menuconfig BR2_TARGET_MXS_BOOTLETS
 	bool "mxs-bootlets"
 	depends on BR2_arm
 	depends on BR2_TARGET_BAREBOX || BR2_LINUX_KERNEL || \

boot/opensbi/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_OPENSBI
+menuconfig BR2_TARGET_OPENSBI
 	bool "opensbi"
 	depends on BR2_riscv
 	help

boot/optee-os/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_OPTEE_OS
+menuconfig BR2_TARGET_OPTEE_OS
 	bool "optee_os"
 	depends on BR2_ARM_CPU_ARMV8A || BR2_ARM_CPU_ARMV7A || BR2_RISCV_64
 	help

boot/syslinux/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_SYSLINUX
+menuconfig BR2_TARGET_SYSLINUX
 	bool "syslinux"
 	depends on BR2_i386 || BR2_x86_64
 	# Make sure at least one of the flavors is installed

boot/ti-k3-r5-loader/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_TI_K3_R5_LOADER
+menuconfig BR2_TARGET_TI_K3_R5_LOADER
 	bool "ti-k3-r5-loader"
 	depends on BR2_aarch64
 	depends on BR2_PACKAGE_HOST_ARM_GNU_TOOLCHAIN_SUPPORTS

boot/uboot/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_UBOOT
+menuconfig BR2_TARGET_UBOOT
 	bool "U-Boot"
 	help
 	  Build "Das U-Boot" Boot Monitor

boot/xilinx-embeddedsw/Config.in

@@ -1,7 +1,7 @@
 comment "xilinx-embeddedsw needs a bare metal toolchain for tuple microblazeel-xilinx-elf"
 	depends on BR2_TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH != "microblazeel-xilinx-elf"
 
-config BR2_TARGET_XILINX_EMBEDDEDSW
+menuconfig BR2_TARGET_XILINX_EMBEDDEDSW
 	bool "xilinx-embeddedsw"
 	depends on BR2_aarch64
 	depends on BR2_TOOLCHAIN_BARE_METAL_BUILDROOT

boot/xilinx-prebuilt/Config.in

@@ -1,4 +1,4 @@
-config BR2_TARGET_XILINX_PREBUILT
+menuconfig BR2_TARGET_XILINX_PREBUILT
 	bool "xilinx-prebuilt"
 	depends on BR2_aarch64
 	help