kernel: Move to Linux v5.1.4-openpower1

powerpc related changes:

 powerpc/traps: Fix the message printed when stack overflows
 powerpc/traps: fix recoverability of machine check handling on book3s/32
 powerpc/smp: Fix NMI IPI xmon timeout
 powerpc/smp: Fix NMI IPI timeout
 powerpc/hugetlb: Don't do runtime allocation of 16G pages in LPAR configuration
 powerpc/ptrace: Simplify vr_get/set() to avoid GCC warning
 powerpc/64s/hash: Fix assert_slb_presence() use of the slbfee. instruction
 powerpc/powernv: Don't reprogram SLW image on every KVM guest entry/exit
 powerpc/kvm: Save and restore host AMR/IAMR/UAMOR
 powerpc/powernv: Make opal log only readable by root

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/configs/witherspoon_defconfig b/openpower/configs/witherspoon_defconfig
index 0f4dc5e..3e2f35f 100644
--- a/openpower/configs/witherspoon_defconfig
+++ b/openpower/configs/witherspoon_defconfig
@@ -16,7 +16,7 @@
 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="5.1.2"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.1.4"
 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"