kernel: Move to Linux v5.4.30-openpower1

The IPR patch was merged v5.4.29.

PowerPC releated changes:

 powerpc: Include .BTF section

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/configs/mihawk_defconfig b/openpower/configs/mihawk_defconfig
index e041d59..0c651ae 100644
--- a/openpower/configs/mihawk_defconfig
+++ b/openpower/configs/mihawk_defconfig
@@ -18,7 +18,7 @@
 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="5.4.25"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.4.30"
 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"