mobicore_driver: add enabling/disabling crypto clock.

Define MC_CRYPTO_CLOCK_MANAGEMENT to activate it.

Change-Id: I05005f6a42b237c86adf696a63e329bf336ef9bb
Signed-off-by: Oana Medvesan <medvesan.oana@gmail.com>
Signed-off-by: Hariprasad Dhalinarasimha <hnamgund@codeaurora.org>
[hnamgund@codeaurora.org: platform.h enable MC_CRYPTO_CLOCK_MANAGEMENT]
Acked-by: Tony Hamilton <tonyh@qti.qualcomm.com>