drm/i915/alpm: Add ALPM register definitions

Add ALPM register definitions for Lunar Lake.

v3:
  - Fix ALPM_CTL2_A address
  - Remove duplicate defines
v2:
  - Use REG_BIT instead of BIT
  - Add commit message

Cc: Jani Nikula <jani.nikula@intel.com>

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240130111130.3298779-2-jouni.hogander@intel.com