x86/platform/ce4100: Prepare for separate mpparse callbacks

Select x86_dtb_parse_smp_config() as SMP configuration parser in
preparation of splitting up the get_smp_config() callback.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240212154639.558085053@linutronix.de