staging: gma500: get control from firmware framebuffer if conflicts

staging: gma500: get control from firmware framebuffer if conflicts

commit aaa5c677910d313ca1318c905c799c459c6f0078 upstream.

Many Linux distributions would enable vesafb in order to display
early stage boot splash. In this case, we will get garbled X
Window screen if running X fbdev on psbfb.

This is because fb0 is occupied by vesafb while psbfb is on fb1.
They tried to drive the same pieces of hardware at the same
time. With unmodified X start-up, it would try to use default
fb0 framebuffer device and unfortunately it is now broken
becaues fb1 supersedes it.

We should let psbfb takeover framebuffer control from vesafb
to get around this problem.

See also commit : 4410f3910947dcea8672280b3adecd53cec4e85e

Signed-off-by: Michael Chang <mchang@novell.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>