440BX boards: Drop more unused #includes from romstage

Romstages of many 440BX boards included headers that are redundant.
Remove them as part of a bigger cleanup effort.

This finishes off what began in https://review.coreboot.org/20693.

Change-Id: I102a4f6e492eb607b7f88d4c6e15072a8b7fdc46
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/20952
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/mainboard/azza/pt-6ibd/romstage.c

@@ -14,7 +14,6 @@
  * GNU General Public License for more details.
  */
 
-#include <stdint.h>
 #include <device/pci_def.h>
 #include <device/pnp_def.h>
 #include <console/console.h>

src/mainboard/compaq/deskpro_en_sff_p600/romstage.c

@@ -14,15 +14,11 @@
  * GNU General Public License for more details.
  */
 
-#include <stdint.h>
 #include <device/pci_def.h>
-#include <arch/io.h>
 #include <device/pnp_def.h>
-#include <stdlib.h>
 #include <console/console.h>
 #include <southbridge/intel/i82371eb/i82371eb.h>
 #include <northbridge/intel/i440bx/raminit.h>
-#include <delay.h>
 #include <cpu/x86/bist.h>
 #include <cpu/intel/romstage.h>
 /* FIXME: This should be PC97307 (but it's buggy at the moment)! */

src/mainboard/msi/ms6119/romstage.c

@@ -14,7 +14,6 @@
  * GNU General Public License for more details.
  */
 
-#include <stdint.h>
 #include <device/pci_def.h>
 #include <device/pnp_def.h>
 #include <console/console.h>

src/mainboard/msi/ms6156/romstage.c

@@ -14,7 +14,6 @@
  * GNU General Public License for more details.
  */
 
-#include <stdint.h>
 #include <device/pci_def.h>
 #include <device/pnp_def.h>
 #include <console/console.h>

src/mainboard/soyo/sy-6ba-plus-iii/romstage.c

@@ -14,7 +14,6 @@
  * GNU General Public License for more details.
  */
 
-#include <stdint.h>
 #include <device/pci_def.h>
 #include <device/pnp_def.h>
 #include <console/console.h>