drm/i915: pass dev_priv explicitly to TRANS_PSR_IIR

Avoid the implicit dev_priv local variable use, and pass dev_priv
explicitly to the TRANS_PSR_IIR register macro.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/3a03109d11e7f55a456c3e5ef28d3ffa69582d3d.1714471597.git.jani.nikula@intel.com


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