cpu/x86: Drop !CPU_INFO_V2 code

Now that all platforms use parallel_mp this is the only codepath used
for cpu_info() local thread storage.

Change-Id: I119214e703aea8a4fe93f83b784159cf86d859d3
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69122
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/security/intel/txt/getsec_enteraccs.S

@@ -227,7 +227,7 @@ cond_clear_var_mtrrs:
 	movd	%esp, %xmm0
 	movd	%ebp, %xmm1
 
-	/* Backup %gs used by CPU_INFO_V2 */
+	/* Backup %gs used by cpu_info() */
 	movl	%gs, %eax
 	movd	%eax, %xmm2
 
@@ -265,7 +265,7 @@ cond_clear_var_mtrrs:
 	movl	%eax, %es
 	movl	%eax, %ss
 	movl	%eax, %fs
-	/* Restore %gs used by CPU_INFO_V2 */
+	/* Restore %gs used by cpu_info */
 	movd	%xmm2, %eax
 	movl	%eax, %gs