libstagefright: changes to return proper HAL Pixel format for video buffers.

  -video component returns NV21_SP color formatted video buffers on qdsp5 targets and
it is mapped to HAL_PIXEL_FORMAT_YCrCb_420_SP pixel format for MDP/GPU to do proper
color conversion.

Conflicts:

	media/libstagefright/OMXCodec.cpp

Change-Id: I9e794994e0f66694255e3cf88036472220e233b5
Signed-off-by: Evan McClain <aeroevan@gmail.com>