pistachio: add 6.1 testing kernel

Configure 6.1 as testing kernel.

Signed-off-by: Zoltan HERPAI <[email protected]>

target/linux/pistachio/Makefile

@@ -13,6 +13,7 @@ CPU_SUBTYPE:=24kf
 SUBTARGETS:=generic
 
 KERNEL_PATCHVER:=5.15
+KERNEL_TESTING_PATCHVER:=6.1
 
 include $(INCLUDE_DIR)/target.mk