all: unmark experimental version

It's been a while we've had those versions, time to unmark them being
experimental. It does not mean everything is perfect, but may gather
some more testing on those versions.

Update samples accordingly.

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

# Alpha specific configuration file

## select ARCH_SUPPORTS_32

## select ARCH_DEFAULT_32

## select ARCH_USE_MMU

## select ARCH_SUPPORTS_WITH_CPU

## select ARCH_SUPPORTS_WITH_TUNE

##

## help The Alpha architecture.