drm/i915/adlp: s/ADLP/ALDERLAKE_P for display and graphics step

Driver refers to the platform Alderlake P as ADLP in places
and ALDERLAKE_P in some. Making the consistent change
to avoid confusion of the right naming convention for
the platform.

v2:
- Unrolled wrapper IS_ADLP_GRAPHICS_STEP and Replace
- Added IS_ALDERLAKE_P() && IS_GRAPHICS_STEP() (Jani/Tvrtko).

v3:
- Removed unused macros of display steps.

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230801135344.3797924-11-dnyaneshwar.bhadane@intel.com