msm: qpnp-power-on: add SEC_ACCESS for s3 debounce

S3 debounce is SEC_ACCESS register. Unlock the register
before updating s3 debounce.

Change-Id: I5cebc35375c6ff8f497c769b25195172f34f5e03
CRs-fixed: 732829
Signed-off-by: Mohan Pallaka <mpallaka@codeaurora.org>