drm/i915: pass dev_priv explicitly to CURBASE

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

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e552df69a4e6a3dbd562ba8c442d0219cda3bfd0.1715774156.git.jani.nikula@intel.com


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