msm: camera: Instead of read_lock use read_lock_irqsave.

Prevent deadlock between tasklet and delete_stream by stopping
irq during delete_stream.

CRs-Fixed: 2076578
Change-Id: Ibcc9fd44403d24112b01150a7d1f3c6e705ea99a
Signed-off-by: Trishansh Bhardwaj <tbhardwa@codeaurora.org>
Signed-off-by: VijayaKumar T M <vtmuni@codeaurora.org>