[ALSA] Fix targets for GUS and OPL4

ALSA sequencer
The the obj targets for GUS and OPL4 are fixed.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/seq/Makefile

@@ -37,6 +37,8 @@ obj-$(CONFIG_SND_SEQ_DUMMY) += snd-seq-dummy.o
 obj-$(CONFIG_SND_VIRMIDI) += snd-seq-virmidi.o snd-seq-midi-event.o
 obj-$(call sequencer,$(CONFIG_SND_RAWMIDI)) += snd-seq-midi.o snd-seq-midi-event.o
 obj-$(call sequencer,$(CONFIG_SND_OPL3_LIB)) += snd-seq-midi-event.o snd-seq-midi-emul.o snd-seq-instr.o
+obj-$(call sequencer,$(CONFIG_SND_OPL4_LIB)) += snd-seq-midi-event.o snd-seq-midi-emul.o snd-seq-instr.o
+obj-$(call sequencer,$(CONFIG_SND_GUS_SYNTH)) += snd-seq-instr.o
 obj-$(call sequencer,$(CONFIG_SND_SBAWE)) += snd-seq-midi-emul.o snd-seq-virmidi.o
 obj-$(call sequencer,$(CONFIG_SND_EMU10K1)) += snd-seq-midi-emul.o snd-seq-virmidi.o
 obj-$(call sequencer,$(CONFIG_SND_TRIDENT)) += snd-seq-midi-emul.o snd-seq-instr.o