drm/i915: pass dev_priv explicitly to PP_DIVISOR

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

Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/28e9f7e3570c15ac5c229048ec0def2e4a667ffc.1716806471.git.jani.nikula@intel.com


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