1280x1024 and 1024x768 @ 32 bpp are supported now.
DVI, Single-link LVDS, Double-link LVDS are all supported.

Environmental variable "monitor" is used to specify monitor port.

A new command "diufb" is introduced to reinitialize monitor
and display a BMP file in the memory. So far, 1-bit, 4-bit,
8-bit and 24-bit BMP formats are supported.

    diufb init
        - initialize the diu driver
    Enable the port specified in the environmental variable "monitor"

    diufb addr
        - display bmp file in memory.
    The bmp image should be no bigger than the resolution, 1280x1024
    for DVI and double-link LVDS, 1024x768 for single-link LVDS.

Note, this driver allocate memory but doesn't free it after use
It is written on purpose -- to avoid a failure of reallocation
due to memory fragement.

ECC of DDR is disabled for DIU performance. L2 data cache is also disabled.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Jon loeliger <jdl@freescale.com>