soc: qcom: dcc_v2: Change HW trigger setting for secure DCC

After secure DCC feature enabled, HW trigger register is used to
indicate whether HLOS has permission to write DCC registers.
Set HW trigger at the end of DCC enabling sequence and clear
HW trigger before write to DCC when DCC is enabled.

Change-Id: Id3c37d56a56e69bca547e2fa1777ef9e47e9340f
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>