msm: camera: ope: Handle race while dumping ope req list

While dumping OPE req list we were not protecting it in context mutex,
this can result into unexpected behaviors. This change take care of
protecting the dump logic with mutex.

CRs-Fixed: 2750458
Change-Id: I916822b498cde3922274c18a06b98c898bff1d65
Signed-off-by: Vikram Sharma <vikramsa@codeaurora.org>