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>

# Alpha specific configuration file

## select ARCH_SUPPORTS_32

## select ARCH_DEFAULT_32

## select ARCH_USE_MMU

## select ARCH_SUPPORT_CPU

## select ARCH_SUPPORT_TUNE

##

## help The Alpha architecture.