samples: update the rpi sample

And use the newly introduced CT_ARCH_SUFFIX at the same time. :-)

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

 # windows config options

 ## depends on ARCH_x86

 ##

 ## select WINDOWS

 ##

 ## help Build a toolchain targeting systems running Windows as host