drm/i915/display: Fill PSR state during hardware configuration read out

So far if we had a mismatch between the state asked and what was
programmed in hardware for PSR, this mismatch would go unnoticed.

So here adding the PSR to the hardware configuration readout,
EDP_PSR_CTL and EDP_PSR2_CTL can't be directly read because its state
flips due to other factors like frontbuffer modifications and CRC.

Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210418002126.87882-1-jose.souza@intel.com