msm: spm_devices: Initialize q2s and set spm_legacy_mode bit at probe

At system boot, cpus and or clusters can remain in reset. CCI SPM will
not be triggered unless SPM_LEGACY_MODE bit is set for the cluster in
reset. Initialize q2s registers and set the SPM_LEGACY_MODE bit at probe.

Also, unset QChannel ignore bit during power collapse due to a hardware
issue.

Change-Id: I07031e0ee276265b66b9fe4e0bb5bab36415b469
Signed-off-by: Karthik Parsha <kparsha@codeaurora.org>