src/soc/intel/{jasperlake,xeon_sp}: Remove unused <string.h>

Found using:
diff <(git grep -l '#include <string.h>' -- src/) <(git grep -l 'STRINGIFY\|memcpy\|memmove\|memset\|memcmp\|memchr\|strdup\|strconcat\|strnlen\|strlen\|strchr\|strncpy\|strcpy\|strcmp\|strncmp\|strspn\|strcspn\|strstr\|strtok_r\|strtok\|atol\|strrchr\|skip_atoi\|snprintf' -- src/)|grep '<'

Change-Id: I0c2da6b0e019c53ac963ebf851243c126ae930b0
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50695
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/soc/intel/jasperlake/bootblock/report_platform.c

@@ -12,7 +12,6 @@
 #include <soc/bootblock.h>
 #include <soc/pch.h>
 #include <soc/pci_devs.h>
-#include <string.h>
 
 static struct {
 	u32 cpuid;

src/soc/intel/xeon_sp/acpi.c

@@ -4,7 +4,6 @@
 #include <intelblocks/acpi.h>
 #include <soc/pci_devs.h>
 #include <soc/util.h>
-#include <string.h>
 
 #include "chip.h"
 

src/soc/intel/xeon_sp/cpx/soc_util.c

@@ -9,7 +9,6 @@
 #include <soc/soc_util.h>
 #include <soc/util.h>
 #include <stdlib.h>
-#include <string.h>
 
 const struct SystemMemoryMapHob *get_system_memory_map(void)
 {