drm/i195/fbc: Add WaFbcNukeOnHostModify

Bspec states that we need to set nuke on modify all to prevent
screen corruption with fbc on skl and kbl.

v2: proper workaround name

References: HSD#2227109, HSDES#1404569388
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465309159-30531-27-git-send-email-mika.kuoppala@intel.com