ath79: enable usbgadget feature

Signed-off-by: Piotr Dymacz <[email protected]>

target/linux/ath79/Makefile

@@ -6,7 +6,7 @@ BOARDNAME:=Atheros ATH79
 CPU_TYPE:=24kc
 SUBTARGETS:=generic mikrotik nand tiny
 
-FEATURES:=ramdisk
+FEATURES:=ramdisk usbgadget
 
 KERNEL_PATCHVER:=5.4
 KERNEL_TESTING_PATCHVER:=5.4