kernel: Move to Linux v5.1.6-openpower1

Powerpc related changes:

 powerpc/64: Fix memcmp reading past the end of src/dest
 powerpc: bpf: Fix generation of load/store DW instructions
 powerpc/security: Fix spectre_v2 reporting
 powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/configs/p8dtu_defconfig b/openpower/configs/p8dtu_defconfig
index dfc8bf5..d1f9279 100644
--- a/openpower/configs/p8dtu_defconfig
+++ b/openpower/configs/p8dtu_defconfig
@@ -17,7 +17,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.1.4"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.1.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"