makefile: untie misc targets from dep files

Such targets as "tags", "cscope" and "clean" doesn't require blob headers to
be rebuilt.
Thi patch remove this dependence.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

Makefile

@@ -182,4 +182,9 @@ cscope:
 	$(Q) $(CSCOPE) -bkqu
 .PHONY: cscope
 
+no-blob-targets := tags clean cscope
+
+ifeq ($(filter-out no-blob-targets, $(MAKECMDGOALS)),)
 -include $(DEPS)
+endif
+