Since 2014 e4defrag was only available for musl/glibc
toolchains in commit d770abad33.
I believe sync_file_range() was already available in 2015 in the uClibc time.
So enable e4defrag. Tested in Qemu on a ext4 filesystem.
Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>