sconfig: Remove mainboard chip.h support

The mainboard chip.h files were (mostly) removed long ago.

Change-Id: I1d5a9381945427c96868fa17756e6ecabb1048b2
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/16080
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/Makefile.inc b/Makefile.inc
index 4d7fd69..7252bcc 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -457,7 +457,7 @@
 $(DEVICETREE_STATIC_C): $(DEVICETREE_FILE) $(objutil)/sconfig/sconfig
 	@printf "    SCONFIG    $(subst $(src)/,,$(<))\n"
 	mkdir -p $(dir $(DEVICETREE_STATIC_C))
-	$(objutil)/sconfig/sconfig $(MAINBOARDDIR) $(DEVICETREE_FILE) $(DEVICETREE_STATIC_C)
+	$(objutil)/sconfig/sconfig $(DEVICETREE_FILE) $(DEVICETREE_STATIC_C)
 
 ramstage-y+=$(DEVICETREE_STATIC_C)
 romstage-y+=$(DEVICETREE_STATIC_C)