bcm47xx: 6.6: set testing kernel

Select 6.6 as testing kernel on bcm47xx.

Signed-off-by: Mieczyslaw Nalewaj <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/15010
Signed-off-by: Robert Marko <[email protected]>

target/linux/bcm47xx/Makefile

@@ -11,6 +11,7 @@ FEATURES:=squashfs usb
 SUBTARGETS:=generic mips74k legacy
 
 KERNEL_PATCHVER:=6.1
+KERNEL_TESTING_PATCHVER:=6.6
 
 define Target/Description
 	Build firmware images for Broadcom based BCM47xx/53xx routers with MIPS CPU, *not* ARM.