makefiles: Remove the obsolete rule for .spec.o files.

Make.rules.in

@@ -133,7 +133,7 @@ filter: dummy
 
 # Implicit rules
 
-.SUFFIXES: .mc .rc .mc.rc .res .spec .spec.o .idl .tlb .h .y .l .tab.c .tab.h .yy.c .ok .man.in .man _c.c _i.c _p.c _s.c @MAINTAINER_MODE@ .sfd .ttf .svg .ico
+.SUFFIXES: .mc .rc .mc.rc .res .idl .tlb .h .y .l .tab.c .tab.h .yy.c .ok .man.in .man _c.c _i.c _p.c _s.c @MAINTAINER_MODE@ .sfd .ttf .svg .ico
 
 .c.o:
 	$(CC) -c $(ALLCFLAGS) -o $@ $<
@@ -153,9 +153,6 @@ filter: dummy
 .rc.res:
 	$(LDPATH) $(RC) $(RCFLAGS) -fo$@ $<
 
-.spec.spec.o:
-	$(WINEBUILD) $(WINEBUILDFLAGS) --dll -o $@ --main-module $(MODULE) --export $<
-
 .idl.h:
 	$(WIDL) $(IDLFLAGS) -h -H $@ $<