[WHY]
We have new bios capabilities enabling s0i2 entry on SMU interrupt. We want
this interrupt to be fired on PSR transitions such that we enter s0i2
when entering PSR active.

[HOW]
Add code to send the SMU interrupt with the appropriate
staticscreen flag when entering and exting PSR. Protect this
code with a config flag since it currently impacts BL PWM.
Signed-off-by: SivapiriyanKumarasamy <sivapiriyan.kumarasamy@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>