drm/i915/psr: Add Panel Replay support to intel_psr2_config_et_valid

Early Transport is possible and in our HW mandatory on eDP Panel
Replay. Add parameter to intel_psr2_config_et_valid to differentiate
validity check for Panel Replay.

v2: fix intel_dp->psr_dpcd[0] check

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240607134917.1327574-9-jouni.hogander@intel.com