drm/i915/display: Compute vrr vsync params

drm/i915/display: Compute vrr vsync params

Compute vrr vsync params in case of FAVT as well instead of
only to AVT mode of operation.

--v2:
- Remove redundant computation for vrr_vsync_start
and vrr_vsync_end(Ankit).

--v3:
- vrr.enable and cmrr.enable check together is not required as both
will be true at the same point in time. (Ankit)
- Replace vrr.enable flag to cmrr.enable, mistakenly added. (Ankit)

Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610072203.24956-9-mitulkumar.ajitkumar.golani@intel.com