drm/i915: Finalize Wa_1408961008:icl

The icl wm1+ underrun w/a has been added to the spec. It changed
slightly from the previous incarnation by requiring that we mirror
the lines watermark and the ignore lines bit from WM0 into WM1.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190228173639.18422-1-ville.syrjala@linux.intel.com


Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Tested-by: Clint Taylor <Clinton.A.Taylor@intel.com>