cpu/x86/mp_init.c: Rename num_concurrent_stacks

This is just the amount of cpus so rename it for simplicity.

Change-Id: Ib2156136894eeda4a29e8e694480abe06da62959
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58699
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/include/cpu/x86/smm.h

@@ -120,7 +120,7 @@ static inline bool smm_points_to_smram(const void *ptr, const size_t len)
 /* SMM Module Loading API */
 
 /* The smm_loader_params structure provides direction to the SMM loader:
- * - num_concurrent_stacks - number of concurrent cpus in handler needing stack
+ * - num_cpus - number of concurrent cpus in handler needing stack
  *                           optional for setting up relocation handler.
  * - per_cpu_save_state_size - the SMM save state size per cpu
  * - num_concurrent_save_states - number of concurrent cpus needing save state
@@ -132,7 +132,7 @@ static inline bool smm_points_to_smram(const void *ptr, const size_t len)
  *             handle sparse APIC id space.
  */
 struct smm_loader_params {
-	size_t num_concurrent_stacks;
+	size_t num_cpus;
 
 	size_t real_cpu_save_state_size;
 	size_t per_cpu_save_state_size;