realtek: 6.6: enable testing kernel

Allow to build the new kernel.

Signed-off-by: Markus Stockhausen <[email protected]>

target/linux/realtek/Makefile

@@ -10,6 +10,7 @@ FEATURES:=ramdisk squashfs
 SUBTARGETS:=rtl838x rtl839x rtl930x rtl931x
 
 KERNEL_PATCHVER:=5.15
+KERNEL_TESTING_PATCHVER:=6.6
 
 define Target/Description
 	Build firmware images for Realtek RTL83xx based boards.