Makefile.inc: Clean up SeaBIOS clean command line

Passing the argments to the sub-make is no longer needed.

Change-Id: Ie4fa3e36c2911eb25f201506df0e79b415d3e9b9
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: http://review.coreboot.org/10656
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/Makefile.inc b/Makefile.inc
index ef9b522..213c56b 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -400,7 +400,7 @@
 	rm -f $(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc
 	rm -f $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.* $(obj)/mainboard/$(MAINBOARDDIR)/dsdt.*
 	rm -f $(obj)/cpu/x86/smm/smm_bin.c $(obj)/cpu/x86/smm/smm.* $(obj)/cpu/x86/smm/smm
-	$(MAKE) -C payloads/external/SeaBIOS -f Makefile.inc clean OUT=$(abspath $(obj)) HOSTCC="$(HOSTCC)" CC="$(CC_x86_32)" LD="$(LD_x86_32)"
+	$(MAKE) -C payloads/external/SeaBIOS -f Makefile.inc clean
 
 clean-target:
 	rm -f $(obj)/coreboot*