[media] s5p-fimc: Changed RGB32 to BGR32

Testing showed that HW produces BGR32 rather then RGB32 as exposed
in the driver. The documentation seems to state the pixels are stored
in little endian order.

Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
[s.nawrocki@samsung.com] replaced "BGRB888, 32 bpp" with "BGRA8888, 32 bpp"
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>