msm: vidc: Remove unused variables and defines

The variables height and width are written to but never read from.
Similarly, the #defines are also unused (most of them are now queried
directly from the firmware).

Change-Id: Ic8a09bba2aad74d0f65f7dd93633f245e9e63418
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>