src: Remove unused 'include <string.h>'

Change-Id: I2a94c3b6282e9915fd2b8136b124740c8a7b774c
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36082
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/soc/mediatek/mt8173/i2c.c

@@ -17,7 +17,6 @@
 #include <console/console.h>
 #include <delay.h>
 #include <device/i2c_simple.h>
-#include <string.h>
 #include <symbols.h>
 #include <timer.h>
 #include <device/mmio.h>

src/soc/mediatek/mt8183/ddp.c

@@ -16,7 +16,6 @@
 #include <device/mmio.h>
 #include <edid.h>
 #include <stdlib.h>
-#include <string.h>
 #include <stddef.h>
 #include <soc/addressmap.h>
 #include <soc/ddp.h>

src/soc/mediatek/mt8183/include/soc/spm.h

@@ -19,7 +19,6 @@
 #include <arch/barrier.h>
 #include <console/console.h>
 #include <soc/addressmap.h>
-#include <string.h>
 #include <stdint.h>
 #include <types.h>