buildsystem: Promote rules.h to default include

Does not fix 3rdparty/, *.S or *.ld or yet.

Change-Id: I66b48013dd89540b35ab219d2b64bc13f5f19cda
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/17656
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/cpu/intel/microcode/microcode.c

@@ -27,7 +27,6 @@
 #include <arch/cpu.h>
 #include <cpu/x86/msr.h>
 #include <cpu/intel/microcode.h>
-#include <rules.h>
 
 #if !defined(__PRE_RAM__)
 #include <smp/spinlock.h>

src/cpu/x86/32bit/entry32.inc

@@ -15,7 +15,6 @@
 
 #include <arch/rom_segs.h>
 #include <cpu/x86/post_code.h>
-#include <rules.h>
 #include <arch/x86/gdt_init.S>
 
 	.code32

src/cpu/x86/pae/pgtbl.c

@@ -20,7 +20,6 @@
 #include <cpu/x86/cr.h>
 #include <cpu/x86/msr.h>
 #include <cpu/x86/pae.h>
-#include <rules.h>
 #include <string.h>
 #include <symbols.h>