scripts: munge .config to handle array variables

Transfrom array variables from pure strings (in the kconfig output)
into proper bash arrays declarations, for feeding to the build scripts.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>

 reporter_name="Bart vdr. Meulen <bartvdrmeulen@gmail.com>"

 reporter_url=""

 reporter_comment="Config to build cross-compiler with mingw as kernel type"