bcm4908: add 6.12 testing kernel

Add 6.12 testing kernel for bcm4908 target.

Signed-off-by: Stefan Kalscheuer <stefan@stklcode.de>
Link: openwrt#20169
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

Author: stklcode

target/linux/bcm4908/Makefile

@@ -10,6 +10,7 @@ CPU_TYPE:=cortex-a53
 SUBTARGETS:=generic
 
 KERNEL_PATCHVER:=6.6
+KERNEL_TESTING_PATCHVER:=6.12
 
 define Target/Description
 	Build firmware images for Broadcom BCM4908 SoC family routers.