msm: camera: tfe: Change csid stop sequence during flush

This change takes care of a race which we see when we halt master
csid immediately and slave csid halt to follow. In some scenarios
after master csid halt, slave gives violation errors.
With this change we are first changing the mode of slave to master
then issue halt commands to both master and slave.

CRs-Fixed: 2773668
Change-Id: Iab7baa41a69b2e4e0a658c7abac29d2dcb80c289
Signed-off-by: Ayush Kumar <ayushkr@codeaurora.org>