util/autoport: Update Makefile.inc generation to Makefile.mk

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: Ib77cb3a0852092ac414fe0160fe10d6e58fcf660
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80127
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/util/autoport/main.go b/util/autoport/main.go
index ed7cb0e..4f5543b 100644
--- a/util/autoport/main.go
+++ b/util/autoport/main.go
@@ -739,7 +739,7 @@
 	}
 
 	if len(BootBlockFiles) > 0 || len(ROMStageFiles) > 0 || len(RAMStageFiles) > 0 || len(SMMFiles) > 0 {
-		mf := Create(ctx, "Makefile.inc")
+		mf := Create(ctx, "Makefile.mk")
 		defer mf.Close()
 		writeMF(mf, BootBlockFiles, "bootblock")
 		writeMF(mf, ROMStageFiles, "romstage")