drm/i915: Use REG_BIT() for bdw+ pipe interrupts

Replace the hand rolled (1<<n) with the modern REG_BIT()
approach for the bdw+ pipe interrupt bits.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240605111832.21373-2-ville.syrjala@linux.intel.com


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