tree: Remove unused <string.h>

Change-Id: I9ed1a82fcd3fc29124ddc406592bd45dc84d4628
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82666
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Yidi Lin <yidilin@google.com>

src/arch/arm64/smbios.c

@@ -6,7 +6,6 @@
 #include <console/console.h>
 #include <smbios.h>
 #include <stdio.h>
-#include <string.h>
 
 static void smbios_processor_id(u32 *processor_id)
 {

src/arch/riscv/include/vm.h

@@ -3,7 +3,6 @@
 #ifndef _VM_H
 #define _VM_H
 
-#include <string.h>
 #include <stdint.h>
 #include <arch/encoding.h>
 

src/arch/x86/smbios.c

@@ -1,6 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
-#include <string.h>
 #include <smbios.h>
 #include <console/console.h>
 #include <arch/cpu.h>