[SPARC]: TCX Framebuffer fixes

Using the same logic as the other framebuffer fixes committed in 2.6.11,
this is a set of fixes to make TCX functional on the console again. Adds
the tcx_pan_display function, sets the
all->info.var.{red,green,blue}.length values to 8, and runs fb_set_cmap.
Also looks for the correct SUNW,tcx prom value.

This patch just slipped through the cracks.

Originally by: Georg Chini <georg.chini@triaton-webhosting.com>

Signed-off-by: Tom 'spot' Callaway <tcallawa@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>