staging: xgifb: delete duplicated YFilter1 data

PAL-M and PAL-N "YFilter1" tables are identical. Replace as follows:

	PALMYFilter1	==> xgifb_palmn_yfilter1
	PALNYFilter1	==> xgifb_palmn_yfilter1

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>