radeonsi: Fix yuv422 corruption seen for non-standard resolutions on GFX10.

The camera preview corrupted for resolutions like 1712x960 or 800x600, because of odd number of blocks of size(64).

This patch will do alignment to nearest EVEN number and Fixing the corruption also.

Signed-off-by: Mandar Sahastrabuddhe msahastr@amd.com