msm: vidc: Fix limit for LTR mode control

Currently, maximum value for VIDC_VIDEO_LTRMODE contrl is set to
LTR_MODE_PERIODIC which is not supported. By limiting it to
LTR_MODE_MANUAL, the control value will stay with in supported range.

CRs-Fixed: 1046755
Change-Id: I85b8ac6dc847343d42cb2f6466137bf43fc1b7c1
Signed-off-by: Amit Shekhar <ashekhar@codeaurora.org>