msm: vidc: Set 0xff to disable hybrid hp

HFI api requires that the driver set layers=0xFF to disable
Hybrid HP, whereas the V4l2 equivalent value is 0x0. Hence we
need to convert to 0xFF before sending to firmware.

CRs-Fixed: 2211180
Change-Id: Iea7f64ecc9ca0ec9546a66ef92e7365714655924
Signed-off-by: Chinmay Sawarkar <chinmays@codeaurora.org>