kconfig: print version in .config

Having the crosstool-NG version in the .config helps in case we
want to reproduce the toolchain with the exact same version of
crosstool-NG.

This also reverts #bb73e7632b54.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

# 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.