drm/i915/xelpd: Handle proper AUX interrupt bits

XE_LPD has new AUX interrupt bits for DDI-D and DDI-E that take the
spots that were used by TC5/TC6 on Display12 platforms.

While we're at it, let's convert the bit definitions for all TGL+ aux
bits over to the modern REG_BIT() notation.

v2:
 - Maintain bit order rather than logical order.  (Lucas)
 - Convert surrounding code to REG_BIT() notation.  (Lucas)

Bspec: 50064
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210512042144.2089071-2-matthew.d.roper@intel.com