cpu/x86/mp_init: use cb_err as status return type in remaining functions

Using cb_err as return type of mp_run_on_aps, mp_run_on_all_aps,
mp_run_on_all_cpus and mp_park_aps clarifies the meaning of the
different return values. This patch also adds the types.h include that
provides the definition of the cb_err enum and checks the return value
of all 4 functions listed above against the enum values instead of
either checking if it's non-zero or less than zero to handle the error
case.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I4b3f03415a041d3ec9cd0e102980e53868b004b0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58494
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

src/include/cpu/x86/mp.h

@@ -117,26 +117,25 @@ enum {
  * Input parameter expire_us <= 0 to specify an infinite timeout.
  * logical_cpu_num = MP_RUN_ON_ALL_CPUS to execute function over all cores (BSP
  * + APs) else specified AP number using logical_cpu_num.
- *
- * All functions return < 0 on error, 0 on success.
  */
-int mp_run_on_aps(void (*func)(void *), void *arg, int logical_cpu_num,
+enum cb_err mp_run_on_aps(void (*func)(void *), void *arg, int logical_cpu_num,
 		long expire_us);
 
 /*
  * Runs func on all APs excluding BSP, with a provision to run calls in parallel
  * or serially per AP.
  */
-int mp_run_on_all_aps(void (*func)(void *), void *arg, long expire_us, bool run_parallel);
+enum cb_err mp_run_on_all_aps(void (*func)(void *), void *arg, long expire_us,
+			      bool run_parallel);
 
 /* Like mp_run_on_aps() but also runs func on BSP. */
-int mp_run_on_all_cpus(void (*func)(void *), void *arg);
+enum cb_err mp_run_on_all_cpus(void (*func)(void *), void *arg);
 
 /*
  * Park all APs to prepare for OS boot. This is handled automatically
  * by the coreboot infrastructure.
  */
-int mp_park_aps(void);
+enum cb_err mp_park_aps(void);
 
 /*
  * SMM helpers to use with initializing CPUs.