cpu/x86/mp_init: remove unused callback arguments

The BSP and AP callback declarations both had an optional argument
that could be passed. In practice that functionality was never used
so drop it.

Change-Id: I47fa814a593b6c2ee164c88d255178d3fb71e8ce
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/14556
Tested-by: build bot (Jenkins)
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Leroy P Leahy <leroy.p.leahy@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/apollolake/cpu.c

@@ -71,7 +71,7 @@ static void bsp_pre_mp_setup(void)
  */
 static struct mp_flight_record flight_plan[] = {
 	/* NOTE: MTRR solution must be calculated before firing up the APs */
-	MP_FR_NOBLOCK_APS(mp_initialize_cpu, NULL, mp_initialize_cpu, NULL),
+	MP_FR_NOBLOCK_APS(mp_initialize_cpu, mp_initialize_cpu),
 };
 
 void apollolake_init_cpus(device_t dev)