viafb: make suspend and resume work (on all machines?)

viafb: make suspend and resume work (on all machines?)

This patch removes the dangerous suspend and resume code that was
developed for VX855 only. After this the framebuffer is expected to
cause no longer serious (freezing) issues on any machines.
However the hardware acceleration is broken now so only doing resume
with unaccelerated framebuffers is save. This did not work previously
as the 2D engine is not mapped if the framebuffer is not accelerated.
The acceleration issue will be addressed later.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Cc: Joseph Chan <JosephChan@via.com.tw>