powerpc/configs: Enable STACK_TRACER and FTRACE_SYSCALLS in some of the configs

Both these config options are generally enabled in distro kernels.
Enable the same in a few powerpc64 configs to get better coverage and
testing.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210524120227.3333208-1-naveen.n.rao@linux.vnet.ibm.com