msm: vidc: correct CVP usecase bandwidth calculations

Client provides bandwidth values in bps (bits per second)
and driver expects in kbps for it calculations. So correct
the values before using them.

Change-Id: Id5f9207f84caf63b478978a174093f5214905c7d
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>