config: Kernel build needs libssl

The kernel build has required libssl for some time now. Most of our CI
has it installed on the host (in the container), so we have not hit any
issues.

This will cause buildroot to check for libssl's presence, and if it is
not found, it will be built.

Fixes: https://github.com/open-power/op-build/issues/2973
Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/configs/p9dsu_defconfig b/openpower/configs/p9dsu_defconfig
index 7098561..63ea47d 100644
--- a/openpower/configs/p9dsu_defconfig
+++ b/openpower/configs/p9dsu_defconfig
@@ -22,6 +22,7 @@
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
 BR2_LINUX_KERNEL_ZIMAGE_EPAPR=y
 BR2_LINUX_KERNEL_XZ=y
+BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
 BR2_PACKAGE_BUSYBOX_CONFIG_FRAGMENT_FILES="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/busybox.fragment"
 BR2_PACKAGE_BUSYBOX_SHOW_OTHERS=y
 BR2_PACKAGE_LINUX_FIRMWARE=y