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>

 # m68k specific configuration file

 ## depends on EXPERIMENTAL

 ##

 ## select ARCH_SUPPORTS_32

 ## select ARCH_DEFAULT_32

 ## select ARCH_DEFAULT_BE

 ## select ARCH_SUPPORTS_WITH_CPU

 ##

 ## help The m68k architecture