Revert "msm: vidc: Update offset and size to optimize cache operations"

This reverts commit be121cc9.
For output buffers, bytesused is 0 when qbuf, and for encoder
it is unable to know how much data will be filled before FBD
and how much data is in cache.
Should do cache ops for the whole buffer.

CRs-Fixed: 2406814
Change-Id: I2c46529c392ea08be6f6297bd33b923c76684fd9
Signed-off-by: Qiwei Liu <qiweil@codeaurora.org>