uapi: Fix linear color format alignment

Fix linear color format alignment. Alignment follows:
Y_Stride: Width should be aligned to 512.
UV_Stride: Width should be aligned to 512.
Y_Scanlines: Height should be aligned to 512.
UV_Scanlines: Height/2 should be aligned to 256.

Change-Id: Id858b656746b574a2b2ef0db6de5478e73eeb136
Signed-off-by: Amit Shekhar <ashekhar@codeaurora.org>