nb/intel/sandybridge: Drop raminit_native.h

After commit adaeb1102186 (nb/intel/sandybridge: Clean up post Haswell SPD mapping API migration), no boards use this header anymore and it
no longer offers original content.

Adjust northbridge code #includes as needed and drop it.

Change-Id: I2785e920bd6188dbfc1a6157351083ec4a2526d0
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78785
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>
diff --git a/src/northbridge/intel/sandybridge/raminit_native.c b/src/northbridge/intel/sandybridge/raminit_native.c
index a46390c..fbdc27a 100644
--- a/src/northbridge/intel/sandybridge/raminit_native.c
+++ b/src/northbridge/intel/sandybridge/raminit_native.c
@@ -12,7 +12,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-#include "raminit_native.h"
+#include "sandybridge.h"
 #include "raminit_common.h"
 #include "raminit_tables.h"