Makefile: Fix Make.dep not updated by config changes

Make.dep file should be updated by .config changed after first make.
There are 2 cases affected for this problem:

 1) Add source files by config symbol
 2) Include header files in #ifdef directive

These 2 cases may not be included in Make.dep and this may prevent the
differential build from working correctly.

libs/libc/Makefile

@@ -154,7 +154,7 @@ endif
 
 # Dependencies
 
-.depend: Makefile $(SRCS)
+.depend: Makefile $(SRCS) $(TOPDIR)$(DELIM).config
 	$(Q) $(MKDEP) --obj-path bin --obj-suffix $(OBJEXT) $(DEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >bin/Make.dep
 ifneq ($(CONFIG_BUILD_FLAT),y)
 	$(Q) $(MKDEP) --obj-path kbin --obj-suffix $(OBJEXT) $(DEPPATH) "$(CC)" -- $(CFLAGS) $(KDEFINE) -- $(SRCS) >kbin/Make.dep

libs/libc/zoneinfo/Makefile

@@ -118,7 +118,7 @@ context: .tzbuilt romfs
 
 # Create dependencies
 
-.depend: Makefile $(SRCS)
+.depend: Makefile $(SRCS) $(TOPDIR)$(DELIM).config
 	$(Q) $(MKDEP) "$(CC)" -- $(CFLAGS) -- $(SRCS) >Make.dep
 	$(Q) touch $@
 

libs/libdsp/Makefile

@@ -65,7 +65,7 @@ $(COBJS): %$(OBJEXT): %.c
 $(BIN): $(OBJS)
 	$(call ARCHIVE, $@, $(OBJS))
 
-.depend: Makefile $(SRCS)
+.depend: Makefile $(SRCS) $(TOPDIR)$(DELIM).config
 	$(Q) $(MKDEP) $(DEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >Make.dep
 	$(Q) touch $@
 

libs/libnx/Makefile

@@ -235,7 +235,7 @@ endif
 
 # Dependencies
 
-.depend: Makefile gensources $(SRCS)
+.depend: Makefile gensources $(SRCS) $(TOPDIR)$(DELIM).config
 	$(Q) $(MKDEP) --obj-path bin --obj-suffix $(OBJEXT) $(DEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >bin/Make.dep
 ifneq ($(CONFIG_BUILD_FLAT),y)
 	$(Q) $(MKDEP) --obj-path kbin --obj-suffix $(OBJEXT) $(DEPPATH) "$(CC)" -- $(CFLAGS) $(KDEFINE) -- $(SRCS) >kbin/Make.dep

libs/libxx/Makefile

@@ -87,7 +87,7 @@ $(BIN):	$(OBJS)
 
 dirlinks::
 
-.depend: Makefile $(SRCS)
+.depend: Makefile $(SRCS) $(TOPDIR)$(DELIM).config
 	$(Q) $(MKDEP) $(DEPPATH) "$(CXX)" -- $(CXXFLAGS) -- $(SRCS) >Make.dep
 	$(Q) touch $@