msm: camera: shut down master clock for eeprom in power down

TXCO counter is not increment due to improper shutdown of the master clock.
Therefore, in this patch we ensure to shutdown the master clock properly.

Change-Id: I0366211a0faabee64d3126f0e93e47ba1aa7af4f
CRs-Fixed: 594203
Signed-off-by: Aditya Jonnalagadda <ajonnala@codeaurora.org>