Deprecating v850, sh, sparc64 in rtems6, remove in rtems7

[Gedare Bloom]

Hello all,

I have filed tickets #4613, #4614, #4615 indicating that the v850, sh,
and sparc64 architecture ports will be deprecated when we release
rtems6 and removed in the development of rtems7. Speak now or forever
hold your peace. (Actually, one can pretty easily revive a port later
on and bring it back up to speed if someone needs it.)

Gedare