package: switch to _CPE_ID_VALID

Now that we document _CPE_ID_VALID, and that it shall be used instead of
setting a default value to one of the other _CPE_ID_* variables, change
all of the existing packages to use it, to avoid any error when we later
extend check-package to validate the sanity ofthe _CPE_ID_* variables.

Mechanical change done within the reference container, running the new
check in check-package, to report the CPE_ID errors:

    $ make check-package 2>/dev/null \
    |awk '{
            split($(1), a, ":"); fname = a[1]
            split($(2), a, "'\''"); val = a[2]
            new_var = $(8); gsub("_CPE_ID_.*", "_CPE_ID_VALID", new_var)
            printf("%s %s %s %s\n", fname, $(8), val, new_var)
    }' \
    |while read fname var val new_var; do
        sed -r -i -e "s/${var}[[:space:]]*=[[:space:]]*${val}/${new_var} = YES/" "${fname}"
    done

    $ git diff -I'CPE_ID_(VENDOR|VALID)'
    [empty]

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/gnuplot/gnuplot.mk

@@ -8,7 +8,7 @@ GNUPLOT_VERSION = 5.4.10
 GNUPLOT_SITE = http://downloads.sourceforge.net/project/gnuplot/gnuplot/$(GNUPLOT_VERSION)
 GNUPLOT_LICENSE = gnuplot license (open source)
 GNUPLOT_LICENSE_FILES = Copyright
-GNUPLOT_CPE_ID_VENDOR = gnuplot_project
+GNUPLOT_CPE_ID_VALID = YES
 
 GNUPLOT_AUTORECONF = YES