bmips: add 6.6 kernel as testing

enable testing kernel version 6.6 for bmips

Signed-off-by: Goetz Goerisch <[email protected]>

target/linux/bmips/Makefile

@@ -10,6 +10,7 @@ SUBTARGETS:=bcm6318 bcm6328 bcm6358 bcm6362 bcm6368 bcm63268
 FEATURES:=gpio squashfs usb
 
 KERNEL_PATCHVER:=6.1
+KERNEL_TESTING_PATCHVER:=6.6
 
 define Target/Description
 	Build firmware images for BCM33xx cable modem chips,