malta: make 5.15 kernel default

In order to begin testing of upcoming kernel.

Signed-off-by: Petr Štetiar <[email protected]>

target/linux/malta/Makefile

@@ -10,8 +10,7 @@ SUBTARGETS:=le be le64 be64
 INITRAMFS_EXTRA_FILES:=
 FEATURES:=cpiogz ext4 ramdisk squashfs targz
 
-KERNEL_PATCHVER:=5.10
-KERNEL_TESTING_PATCHVER:=5.15
+KERNEL_PATCHVER:=5.15
 
 include $(INCLUDE_DIR)/target.mk