drm/i915/psr: Check if final vblank is sufficient for PSR features

drm/i915/psr: Check if final vblank is sufficient for PSR features

Currently, wake line latency checks rely on the vblank length,
which does not account for either the extra vblank delay for icl/tgl or for
the optimized guardband which will come into picture later at some point.

Validate whether the final vblank (with extra vblank delay) or guardband
is sufficient to support wake line latencies required by Panel Replay and
PSR2 selective update. Disable the PSR features if their wake requirements
cannot be accomodated.

v2: Add comments clarifying wake line checks and rationale for not
    resetting SCL. (Jouni)
v3: Reset other psr flags based on features that are dropped. (Jouni)
v4: Update commit message.
v5: Remove early return and simplify the checking for wakelines. (Jouni)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Link: https://lore.kernel.org/r/20251016055415.2101347-9-ankit.k.nautiyal@intel.com