mm-video-v4l2: vdec: Correct order of reading color primaries

According to H265 spec, the color primaries should be in G,B,R
order. But in the exisisting code they are read in R, G, B order.
Correct the order of reading bitstream as per the specification.

(cherry-picked from:
https://partner-android-review.googlesource.com/c/platform/hardware/qcom/media/+/1123749/)
Bug: 111799726
Bug: 112443029
Change-Id: Ic6703dcf7878c27e3e18e437039ddb74cf8d32d6