msm: camera: calculate RDI bandwidth properly

When requesting RDI AB?IB, need to consider the bit width of RDI interface.
Since bus interface expect a byte based calculation.

Change-Id: Ib01563250adaf967c411bf660ba9f9f516923625
Signed-off-by: Peter Liu <pingchie@codeaurora.org>
Signed-off-by: Bharat Pawar <bpawar@codeaurora.org>
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>