drm/i915/flipq: Implement flip queue based commit path

drm/i915/flipq: Implement flip queue based commit path

Support commits via the flip queue (as opposed to DSB or MMIO).

As it's somewhat unknown if we can actually use it is currently
gated behind the new use_flipq modparam, which defaults to disabled.

The implementation has a bunch of limitations that would need
real though to solve:
- disabled when PSR is used
- disabled when VRR is used
- color management updates not performed via the flip queue

v2: Don't use flip queue if there is no dmc
v3: Use intel_flipq_supported()
v3: Configure PKG_C_LATENCY appropriately
    Ignore INT_VECTOR if there is a real PIPEDMC interrupt
    (nothing in the hw appears to clear INT_VECTOR)
v4: Leave added_wake_time=0 when flip queue isn't used, to
    avoid needleslly increasing pkg_c_latency on lnl/ptl due
    to Wa_22020432604. This is a bit racy though...
    Use IS_DISPLAY_VER()

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250624170049.27284-6-ville.syrjala@linux.intel.com