firmware: Correct dependency on CONFIG_EXTRA_FIRMWARE_DIR

When CONFIG_EXTRA_FIRMWARE_DIR gets changed, the filename in the .S file
(which uses .incbin to include the binary) needs to change. When we
renamed the BUILTIN_FIRMWARE_DIR option to EXTRA_FIRMWARE_DIR, we forgot
to update the manual dependency in firmware/Makefile, so it was
depending on a non-existent file in include/config/
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

firmware/Makefile

@@ -136,7 +136,7 @@ $(patsubst %,$(obj)/%.gen.S, $(fw-shipped-y)): %: $(wordsize_deps) \
 		| $(objtree)/$$(dir %)
 	$(call cmd,fwbin,$(patsubst %.gen.S,%,$@))
 $(patsubst %,$(obj)/%.gen.S, $(fw-external-y)): %: $(wordsize_deps) \
-		include/config/builtin/firmware/dir.h | $(objtree)/$$(dir %)
+		include/config/extra/firmware/dir.h | $(objtree)/$$(dir %)
 	$(call cmd,fwbin,$(fwabs)/$(patsubst $(obj)/%.gen.S,%,$@))
 
 # The .o files depend on the binaries directly; the .S files don't.