vidc: 1080p: Reset meta data offset to zero

For multi-resolution clips, the meta data offset used while
doing cache clean of meta data buffer is from the previous
resolution & resulting in kernel panic. Resetting the offset
to zero during meta data buffer initialization for new
resolution fixes the issue.

CRs-fixed: 386245
Signed-off-by: Rajeshwar Kurapaty <rkurapat@codeaurora.org>
(cherry picked from commit 16145bcbd6af8db0eebc0eedec1f01ee1b0b3635)

Change-Id: I249c0cd220f8fa4f815488a9a321a398752329e4
Signed-off-by: Gopal Goberu <ggober@codeaurora.org>