lcd: align bmp header when uncopmressing image

When compressed image is loaded, it must be decompressed
to an aligned address + 2 to avoid unaligned access exception
on some ARM platforms.

Signed-off-by: Piotr Wilczek <p.wilczek@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Anatolij Gustschin <agust@denx.de>
CC: Wolfgang Denk <wd@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>