util/crossgcc: Add build-without-gdb Makefile target

Change-Id: I5d02f1a23e54aa67be0cc01d921898c28c22f8e4
Signed-off-by: Peter Stuge <peter@stuge.se>
Reviewed-on: http://review.coreboot.org/16
Tested-by: build bot (Jenkins)
Reviewed-by: Marshall Buschman <mbuschman@lucidmachines.com>

util/crossgcc/Makefile

@@ -3,6 +3,10 @@ all: build
 build:
 	./buildgcc
 
+.PHONY: build-without-gdb
+build-without-gdb:
+	./buildgcc --skip-gdb
+
 clean:
 	rm -rf xgcc