powerpc: Add DIU platform code for MPC8610HPCD

Add platform code to support Freescale DIU.  The platform code includes
framebuffer memory allocation, pixel format, monitor port, etc.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Timur Tabi <timur@freescale.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>