Intel: Add common header file for CAR setup

When passing '-ffreestanding' the 'main' romstage.c may no longer
necessarily be considered the entry point.

From the C specification in 5.1.2.1 Freestanding environment;

"In a freestanding environment (in which C program execution may take
place without any benefit of an operating system), the name and type of
the function called at program startup are implementation-defined."

Clang complains about these being missing as Clang is somewhat more
strict about the spec than GNU/GCC is. An advantage here is that a
different entry-point type-signature shall now be warned about at
compile time.

Change-Id: I467001adabd47958c30c9a15e3248e42ed1151f3
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5872
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/mainboard/iei/juki-511p/romstage.c

@@ -32,6 +32,7 @@
 
 #define SERIAL_DEV PNP_DEV(0x3f0, W83977F_SP1)
 
+#include <cpu/intel/car.h>
 static void main(unsigned long bist)
 {
 	w83977f_enable_serial(SERIAL_DEV, CONFIG_TTYS0_BASE);

src/mainboard/iei/nova4899r/romstage.c

@@ -32,6 +32,7 @@
 
 #include "northbridge/amd/gx1/raminit.c"
 
+#include <cpu/intel/car.h>
 static void main(unsigned long bist)
 {
 	w83977tf_enable_serial(SERIAL_DEV, CONFIG_TTYS0_BASE);

src/mainboard/iei/pcisa-lx-800-r10/romstage.c

@@ -49,6 +49,7 @@ int spd_read_byte(unsigned int device, unsigned int address)
 #include "cpu/amd/geode_lx/syspreinit.c"
 #include "cpu/amd/geode_lx/msrinit.c"
 
+#include <cpu/intel/car.h>
 void main(unsigned long bist)
 {
 

src/mainboard/iei/pm-lx-800-r11/romstage.c

@@ -53,6 +53,7 @@ int spd_read_byte(unsigned int device, unsigned int address)
 #include <cpu/amd/geode_lx/syspreinit.c>
 #include <cpu/amd/geode_lx/msrinit.c>
 
+#include <cpu/intel/car.h>
 void main(unsigned long bist)
 {
 	static const struct mem_controller memctrl[] = {

src/mainboard/iei/pm-lx2-800-r10/romstage.c

@@ -53,6 +53,7 @@ int spd_read_byte(unsigned int device, unsigned int address)
 #include <cpu/amd/geode_lx/syspreinit.c>
 #include <cpu/amd/geode_lx/msrinit.c>
 
+#include <cpu/intel/car.h>
 void main(unsigned long bist)
 {
 	static const struct mem_controller memctrl[] = {