cpu/x86/smm/smm_module_loaderv2.c: Constify setup_stub()

Change-Id: I6648d0710bc0ba71cfbaaf4db7a8c1f33bbc9b35
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51183
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/cpu/x86/smm/smm_module_loaderv2.c

@@ -324,9 +324,9 @@ static int smm_stub_place_staggered_entry_points(char *base,
  * This module setup code works for the default (0x30000) SMM handler setup and the
  * permanent SMM handler.
  */
-static int smm_module_setup_stub(void *smbase, size_t smm_size,
+static int smm_module_setup_stub(void *const smbase, const size_t smm_size,
 				 struct smm_loader_params *params,
-				 void *fxsave_area)
+				 void *const fxsave_area)
 {
 	size_t total_save_state_size;
 	size_t smm_stub_size;