pm3fb: copyarea and partial imageblit suppor

This patch adds accelerated copyarea and partially accelerated imageblit
functions. There is also fixed one register address in the pm3fb.h file.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>