kernel: Move to Linux 4.17.4-openpower1

 powerpc/64s: Fix DT CPU features Power9 DD2.1 logic
 powerpc/64s/radix: Fix radix_kvm_prefetch_workaround paca access of not possible CPU
 powerpc/fadump: Unregister fadump on kexec down path.
 powerpc/powernv/cpuidle: Init all present cpus for deep states
 powerpc/powernv: copy/paste - Mask SO bit in CR
 powerpc/powernv/ioda2: Remove redundant free of TCE pages
 powerpc/ptrace: Fix enforcement of DAWR constraints
 powerpc/perf: Fix memory allocation for core-imc based on num_possible_cpus()
 powerpc/ptrace: Fix setting 512B aligned breakpoints with PTRACE_SET_DEBUGREG
 powerpc/pkeys: Detach execute_only key on !PROT_EXEC
 powerpc/mm/hash: Add missing isync prior to kernel stack SLB switch
 cpuidle: powernv: Fix promotion from snooze if next state disabled

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/configs/p9dsu_defconfig b/openpower/configs/p9dsu_defconfig
index 009a8f5..b97ce49 100644
--- a/openpower/configs/p9dsu_defconfig
+++ b/openpower/configs/p9dsu_defconfig
@@ -14,7 +14,7 @@
 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="4.17.3"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.17.4"
 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"