drm/i915/alpm: Calculate ALPM Entry check

ALPM Entry Check represents the number of lines needed to put the main link
to sleep and keep it in the sleep state before it can be taken out of the
SLEEP state (eDP requires the main link to be in the SLEEP state for a
minimum of 5us).

Bspec: 71477

v2: move display version check into _lnl_compute_alpm_param

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/20240130111130.3298779-4-jouni.hogander@intel.com