nb/intel/x4x: Use parallel MP init

Use parallel MP init code to initialize all AP's.

Also remove guards around CPU code where all platforms now use
parallel MP init.

This also removes the code required on lapic init path for
model_6fx, model_1017x and model_f4x as all platforms now use the
parallel MP code.

Tested on Intel DG41WV, shaves off about 90ms on a quad core.

Change-Id: Id5a2729f5bf6b525abad577e63d7953ae6640921
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/25601
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/x4x/Kconfig b/src/northbridge/intel/x4x/Kconfig
index 117ac03..6f3546f 100644
--- a/src/northbridge/intel/x4x/Kconfig
+++ b/src/northbridge/intel/x4x/Kconfig
@@ -29,6 +29,7 @@
 	select POSTCAR_STAGE
 	select POSTCAR_CONSOLE
 	select SMM_TSEG
+	select PARALLEL_MP
 
 config CBFS_SIZE
 	hex