ath79: lzma-loader: fix & re-enable per-board CONFIG_BOARD_DEV

Back in the AR71XX days, the lzma-loader code could be customized
based on the $BOARD variable. These would be passed as a
compile-time -DCONFIG_BOARD_$DEVICE_MODEL flag to the compiler.
Hence, the lzma-loader would be able to include device-specific
fixups.

Note: There's still a fixup for the TpLink TL-WR1043ND V1 found
in the lzma-loader's board.c code. But since the days of AR71XX
I couldn't find a forum post or bug reported. So, I left it
as is to not break anything by enabling it.

=> If you have a TL-WR1043ND V1 and you have problem with
the ethernet: let me know. Because otherwise, the fixup
might simply no longer needed with ath79 and it can be removed.

Signed-off-by: Christian Lamparter <[email protected]>

target/linux/ath79/image/Makefile

@@ -27,14 +27,17 @@ define Build/loader-common
 endef
 
 define Build/loader-kernel
-	$(call Build/loader-common,LOADER_DATA="$@")
+	$(call Build/loader-common, \
+		LOADER_DATA="$@" \
+		BOARD="$(DEVICE_NAME)" )
 endef
 
 define Build/loader-okli-compile
 	$(call Build/loader-common, \
 		FLASH_OFFS=$(LOADER_FLASH_OFFS) \
 		FLASH_MAX=$(LOADER_FLASH_MAX) \
-		KERNEL_MAGIC=$(LOADER_KERNEL_MAGIC) )
+		KERNEL_MAGIC=$(LOADER_KERNEL_MAGIC) \
+		BOARD="$(DEVICE_NAME)" )
 endef
 
 # Arguments: <output name> <kernel offset>