arch/x86,cpu/x86,lib/thread: Remove usage of cpu_info from lib/thread

We only ever start and execute threads on the BSP. By explicitly
checking to see if the CPU is the BSP we can remove the dependency on
cpu_info. With this change we can in theory enable threads in all
stages.

BUG=b:194391185, b:179699789
TEST=Boot guybrush to OS and verify coop multithreading still works

Suggested-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: Iea4622d52c36d529e100b7ea55f32c334acfdf3e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58199
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/x86/cpu_info.S.inc

@@ -2,9 +2,6 @@
 
 /* Push struct cpu_info */
 .macro push_cpu_info index=$0
-#if CONFIG(COOP_MULTITASKING)
-	push	$0	/* *thread */
-#endif
 	push	\index	/* index */
 	push	$0	/* *cpu */
 .endm

src/cpu/x86/lapic/lapic_cpu_init.c

@@ -253,7 +253,6 @@ static int start_cpu(struct device *cpu)
 	info->index = index;
 	info->cpu   = cpu;
 	cpu_add_map_entry(info->index);
-	thread_init_cpu_info_non_bsp(info);
 
 	/* Advertise the new stack and index to start_cpu */
 	secondary_stack = stack_top;

src/cpu/x86/mp_init.c

@@ -193,7 +193,6 @@ static void asmlinkage ap_init(unsigned int cpu)
 	info->cpu = cpus_dev[cpu];
 
 	cpu_add_map_entry(info->index);
-	thread_init_cpu_info_non_bsp(info);
 
 	/* Fix up APIC id with reality. */
 	info->cpu->path.apic.apic_id = lapicid();