trace: Fix user emulator dependency on trace objects

On a clean build, after generating trace.h, make would recurse into *-*-user
without a clue how to build ../trace.o (added to $(obj-y) in Makefile.target)
since its generation rule is in the main Makefile.
The softmmus are seemingly unaffected because the $(TOOLS), which each have
a dependency on $(trace-obj-y), are built first for the build-all target.

Add a dependency on $(trace-obj-y) for %-user, as done for the qemu-* tools.

Let's be paranoid and do the same for %-softmmu while at it, just in case
someone messes with $(TOOLS) or calls the Makefile target directly.
Signed-off-by: NAndreas Färber <andreas.faerber@web.de>
Acked-by: NStefan Weil <weil@mail.berlios.de>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Prerna Saxena <prerna@linux.vnet.ibm.com>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Makefile

@@ -80,9 +80,9 @@ include $(SRC_PATH)/Makefile.objs
 endif
 
 $(common-obj-y): $(GENERATED_HEADERS)
-$(filter %-softmmu,$(SUBDIR_RULES)): $(common-obj-y) subdir-libdis
+$(filter %-softmmu,$(SUBDIR_RULES)): $(trace-obj-y) $(common-obj-y) subdir-libdis
 
-$(filter %-user,$(SUBDIR_RULES)): $(GENERATED_HEADERS) subdir-libdis-user subdir-libuser
+$(filter %-user,$(SUBDIR_RULES)): $(GENERATED_HEADERS) $(trace-obj-y) subdir-libdis-user subdir-libuser
 
 ROMSUBDIR_RULES=$(patsubst %,romsubdir-%, $(ROMS))
 romsubdir-%: