powerpc/configs/64s: Enable SLAB hardening options

Fedora & CentOS enable these.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230414132415.821564-15-mpe@ellerman.id.au

arch/powerpc/configs/ppc64_defconfig

@@ -81,6 +81,10 @@ CONFIG_BINFMT_MISC=m
 CONFIG_ZSWAP=y
 CONFIG_Z3FOLD=y
 CONFIG_ZSMALLOC=y
+# CONFIG_SLAB_MERGE_DEFAULT is not set
+CONFIG_SLAB_FREELIST_RANDOM=y
+CONFIG_SLAB_FREELIST_HARDENED=y
+CONFIG_SHUFFLE_PAGE_ALLOCATOR=y
 # CONFIG_COMPAT_BRK is not set
 CONFIG_MEMORY_HOTPLUG=y
 CONFIG_MEMORY_HOTREMOVE=y