libstagefright: Changes to support NV21 pixel format Video buffer

-video component returns NV21 color format on qdsp5 targets and it is
mapped to correct HAL Pixed format.

Patchset 1: Add QCOM_HARDWARE ifdefs.

Conflicts:

	media/libstagefright/OMXCodec.cpp

Change-Id: I6b427a2e8b498103ea6c428b62112e8ce1517b2c
Signed-off-by: Evan McClain <aeroevan@gmail.com>