build: Drop duplicate asm recipe

And move the asm recipe to the top-level Makefile next to the other
local pattern rules for .o files.

Makefile

@@ -56,6 +56,11 @@ COMPILE_HOSTC = $(call COMPILE,HOSTCC)
 %_host.o: %.c
 	$(COMPILE_HOSTC)
 
+%.o: %.asm
+	$(DEPYASM) $(YASMFLAGS) -I $(<D)/ -M -o $@ $< > $(@:.o=.d)
+	$(YASM) $(YASMFLAGS) -I $(<D)/ -o $@ $<
+	-$(STRIP) $(STRIPFLAGS) $@
+
 %.i: %.c
 	$(CC) $(CCFLAGS) $(CC_E) $<
 

library.mak

@@ -10,11 +10,6 @@ INSTHEADERS := $(INSTHEADERS) $(HEADERS:%=$(SUBDIR)%)
 all-$(CONFIG_STATIC): $(SUBDIR)$(LIBNAME)
 all-$(CONFIG_SHARED): $(SUBDIR)$(SLIBNAME)
 
-$(SUBDIR)x86/%.o: $(SUBDIR)x86/%.asm
-	$(DEPYASM) $(YASMFLAGS) -I $(<D)/ -M -o $@ $< > $(@:.o=.d)
-	$(YASM) $(YASMFLAGS) -I $(<D)/ -o $@ $<
-	-$(STRIP) $(STRIPFLAGS) $@
-
 LIBOBJS := $(OBJS) $(SUBDIR)%.h.o $(TESTOBJS)
 $(LIBOBJS) $(LIBOBJS:.o=.i):   CPPFLAGS += -DHAVE_AV_CONFIG_H
 

tests/checkasm/x86/Makefile

 CHECKASMOBJS-$(HAVE_YASM) += x86/checkasm.o
-
-tests/checkasm/x86/%.o: tests/checkasm/x86/%.asm
-	$(DEPYASM) $(YASMFLAGS) -I $(<D)/ -M -o $@ $< > $(@:.o=.d)
-	$(YASM) $(YASMFLAGS) -I $(<D)/ -o $@ $<
-	-$(STRIP) $(STRIPFLAGS) $@