lantiq: falcon: mark as source only sub target

The sub target does not support network and there are not so many users
out there, just mark it as source only, so we do jot have to build it.

The quality is not worse than before, it just does not make much sense
to build this automatically.

Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/lantiq/falcon/target.mk

@@ -1,7 +1,7 @@
 ARCH:=mips
 SUBTARGET:=falcon
 BOARDNAME:=Falcon
-FEATURES+=nand
+FEATURES+=nand source-only
 CPU_TYPE:=24kc
 
 DEFAULT_PACKAGES+= kmod-leds-gpio \