drm/i915/snps: pass encoder to intel_snps_phy_update_psr_power_state()

Pass encoder to intel_snps_phy_update_psr_power_state(). The encoder
will be more helpful than just port in the subsequent changes.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4711919a9834cf4a49fd665009ba9d44b4b42bc4.1710949619.git.jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>