src: Use 'include <string.h>' when appropriate

Drop 'include <string.h>' when it is not used and
add it when it is missing.
Also extra lines removed, or added just before local includes.

Change-Id: Iccac4dbaa2dd4144fc347af36ecfc9747da3de20
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31966
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
diff --git a/src/northbridge/intel/gm45/acpi.c b/src/northbridge/intel/gm45/acpi.c
index 301743ce..decf712 100644
--- a/src/northbridge/intel/gm45/acpi.c
+++ b/src/northbridge/intel/gm45/acpi.c
@@ -15,13 +15,13 @@
  */
 
 #include <types.h>
-#include <string.h>
 #include <console/console.h>
 #include <arch/acpi.h>
 #include <arch/acpigen.h>
 #include <device/device.h>
 #include <device/pci.h>
 #include <device/pci_ops.h>
+
 #include "gm45.h"
 
 unsigned long acpi_fill_mcfg(unsigned long current)
diff --git a/src/northbridge/intel/gm45/northbridge.c b/src/northbridge/intel/gm45/northbridge.c
index 40e4f61..f011cce 100644
--- a/src/northbridge/intel/gm45/northbridge.c
+++ b/src/northbridge/intel/gm45/northbridge.c
@@ -20,11 +20,11 @@
 #include <device/device.h>
 #include <device/pci.h>
 #include <stdlib.h>
-#include <string.h>
 #include <cpu/cpu.h>
 #include <boot/tables.h>
 #include <arch/acpi.h>
 #include <cpu/intel/smm/gen1/smi.h>
+
 #include "chip.h"
 #include "gm45.h"
 
diff --git a/src/northbridge/intel/gm45/pcie.c b/src/northbridge/intel/gm45/pcie.c
index c470b81..4199274 100644
--- a/src/northbridge/intel/gm45/pcie.c
+++ b/src/northbridge/intel/gm45/pcie.c
@@ -16,7 +16,6 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include <string.h>
 #include <device/pci_ops.h>
 #include <device/pci_def.h>
 #include <console/console.h>
diff --git a/src/northbridge/intel/gm45/pm.c b/src/northbridge/intel/gm45/pm.c
index a447a23..d96bcf4 100644
--- a/src/northbridge/intel/gm45/pm.c
+++ b/src/northbridge/intel/gm45/pm.c
@@ -16,7 +16,6 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include <string.h>
 #include <device/pci_def.h>
 #include <cpu/x86/msr.h>
 #include <cpu/intel/speedstep.h>
diff --git a/src/northbridge/intel/gm45/romstage.c b/src/northbridge/intel/gm45/romstage.c
index 7335ac9..09439f2 100644
--- a/src/northbridge/intel/gm45/romstage.c
+++ b/src/northbridge/intel/gm45/romstage.c
@@ -27,6 +27,7 @@
 #include <northbridge/intel/gm45/gm45.h>
 #include <southbridge/intel/i82801ix/i82801ix.h>
 #include <southbridge/intel/common/gpio.h>
+#include <string.h>
 
 #define LPC_DEV PCI_DEV(0, 0x1f, 0)
 #define MCH_DEV PCI_DEV(0, 0, 0)
diff --git a/src/northbridge/intel/gm45/thermal.c b/src/northbridge/intel/gm45/thermal.c
index 3ed75b3..1629a67 100644
--- a/src/northbridge/intel/gm45/thermal.c
+++ b/src/northbridge/intel/gm45/thermal.c
@@ -16,11 +16,10 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include <string.h>
 #include <device/pci_def.h>
 #include <spd.h>
-#include "delay.h"
 
+#include "delay.h"
 #include "gm45.h"
 
 void raminit_thermal(const sysinfo_t *sysinfo)