layerscape: switch to Kernel 5.15 by default

Getting ready for the next release.

Tested-by: Pawel Dembicki <[email protected]>
Signed-off-by: Paul Spooren <[email protected]>

target/linux/layerscape/Makefile

@@ -6,8 +6,9 @@ include $(TOPDIR)/rules.mk
 
 BOARD:=layerscape
 BOARDNAME:=NXP Layerscape
-KERNEL_PATCHVER:=5.10
-KERNEL_TESTING_PATCHVER:=5.15
+
+KERNEL_PATCHVER:=5.15
+
 FEATURES:=squashfs nand usb pcie gpio fpu ubifs ext4 rootfs-part boot-part
 SUBTARGETS:=armv8_64b armv7