ar71xx/generic: add generic- prefix to vendor-specific image Makefile snippets

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

target/linux/ar71xx/image/Makefile

@@ -13,11 +13,11 @@ KERNEL_LOADADDR = 0x80060000
 DEVICE_VARS += BOARDNAME CMDLINE CONSOLE IMAGE_SIZE LOADER_TYPE
 
 ifeq ($(SUBTARGET),generic)
-include ./tp-link.mk
-include ./ubnt.mk
 include ./generic.mk
-include ./legacy-devices.mk
-include ./senao.mk
+include ./generic-legacy-devices.mk
+include ./generic-senao.mk
+include ./generic-tp-link.mk
+include ./generic-ubnt.mk
 endif
 ifeq ($(SUBTARGET),nand)
 include ./nand.mk