msm: scm-pas: Fix BW voting and clock control

- The secure side might use the crypto HW during the init image call. So
  enable the required clocks and make BW votes in pas_init_image() before
  calling the secure side.
- Don't treat these steps as optional in pas_auth_and_reset()

CRs-fixed: 471930
Change-Id: Idd2f6643dfa7b18c596b8ec697691906de194bb4
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>