nb/intel/i945: Use parallel MP init

Use the parallel mp init path to initialize AP's. This should result
in a moderate speedup.

Tested on Intel D945GCLF (1 core 2 threads), still boots fine and is
26ms faster compared to lapic_cpu_init.

This removes the option to disable HT siblings.

Change-Id: I955551b99e9cbc397f99c2a6bd355c6070390bcb
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/25600
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

src/southbridge/intel/i82801gx/lpc.c

@@ -353,7 +353,8 @@ static void i82801gx_lock_smm(struct device *dev)
 	/* Don't allow evil boot loaders, kernels, or
 	 * userspace applications to deceive us:
 	 */
-	smm_lock();
+	if (!IS_ENABLED(CONFIG_PARALLEL_MP))
+		smm_lock();
 
 #if TEST_SMM_FLASH_LOCKDOWN
 	/* Now try this: */