cpu/x86: Remove cpu parameter to ap_init

We now pre-populate cpu_info before jumping to the C handler. We no
longer need this parameter.

I moved the stack alignment closer to the actual invocation of the C
handler so it's easier to reason about.

BUG=b:194391185, b:179699789
TEST=Boot guybrush to OS and verify all CPUs still function

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I8997683b6613b7031784cabf7039a400f0efdea1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58147
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/cpu/x86/mp_init.c

@@ -180,7 +180,7 @@ static void park_this_cpu(void *unused)
 
 /* By the time APs call ap_init() caching has been setup, and microcode has
  * been loaded. */
-static void asmlinkage ap_init(unsigned int cpu)
+static void asmlinkage ap_init(void)
 {
 	struct cpu_info *info = cpu_info();