msm:camera:isp: Remove unwanted register update

At some cases, if register update is not issued
from user space, due to the register update at
frame drop config, partial settings may be
applied. Remove the unwanted register update
at frame drop configuration.

Change-Id: I717a6c29ae997a3702510f41ef833ec72053b3df
Signed-off-by: Meera Gande <mgande@codeaurora.org>