bcm53xx: use default SUPPORTED_DEVICES for Meraki MR32

Since the new global SUPPORTED_DEVICES are now available in bcm53xx
as well, we do not need to specify an explicit value for the MR32
anymore.

Signed-off-by: Adrian Schmutzler <[email protected]>

target/linux/bcm53xx/image/Makefile

@@ -335,10 +335,8 @@ define Device/meraki_mr32
 	pad-to 10362880
   KERNEL := kernel-bin | fit none $$(DTS_DIR)/$$(DEVICE_DTS).dtb
   IMAGES := sysupgrade.bin
-  IMAGE/sysupgrade.bin := sysupgrade-tar | append-metadata
-
 # Currently the only device that uses the new image check
-  SUPPORTED_DEVICES := meraki,mr32
+  IMAGE/sysupgrade.bin := sysupgrade-tar | append-metadata
 
 # The loader is specifically looking for fdt@2:
 # [    3.190000] find_itb_subimage: error finding fdt@2: FDT_ERR_NOTFOUND