check: Only test ac97 when it is compiled in

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>

tests/Makefile.include

@@ -226,8 +226,8 @@ check-qtest-pci-$(CONFIG_NE2000_PCI) += tests/ne2000-test$(EXESUF)
 gcov-files-pci-$(CONFIG_NE2000_PCI) += hw/net/ne2000.c
 check-qtest-pci-y += tests/nvme-test$(EXESUF)
 gcov-files-pci-y += hw/block/nvme.c
-check-qtest-pci-y += tests/ac97-test$(EXESUF)
-gcov-files-pci-y += hw/audio/ac97.c
+check-qtest-pci-$(CONFIG_AC97) += tests/ac97-test$(EXESUF)
+gcov-files-pci-$(CONFIG_AC97) += hw/audio/ac97.c
 check-qtest-pci-$(CONFIG_ES1370) += tests/es1370-test$(EXESUF)
 gcov-files-pci-$(CONFIG_ES1370) += hw/audio/es1370.c
 check-qtest-pci-y += $(check-qtest-virtio-y)