powerpc/configs/64s: Enable CONFIG_KALLSYMS_ALL

This adds all symbols required for use case like
livepatching. Distros already enable this config
and enabling this increases build time by 3%
(in a power9 128 cpu setup) and almost no size
changes for vmlinux.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250116073419.344453-1-maddy@linux.ibm.com