camera: native: make video buffers 4K aligned.

This change makes sure that the video buffers are
4K aligned in size, as required by the video encoder.
This requriement was implicitly applied by the PMEM
driver but needs to be made manually for ION.

This is port of:
https://www.codeaurora.org/cgit/quic/la/platform/hardware/qcom/camera/commit/?id=f7f1b8c9c963d03c95a5c9d631cbc3e9fda59437

Change-Id: I215b2f077e1558ba93ab6be64330562b05b14b3c
Camera: Preview buffer length correction in PCB

Gralloc is creating the buffers in an aligned fashion because of which buffer size created for
each preview frame is little more than the required (width*height*1.5).
This fix corrects the memory back to original ((width*height*1.5)) by removing the extra space created while doing PCB.

This is port of:
https://www.codeaurora.org/cgit/quic/la/platform/hardware/qcom/camera/commit?id=16f3d71795422810d16ca68195dc7cf69cf19c6a

Change-Id: I515094cb3e41d4f870552879222a90e72b13e660