src/ec: Remove unused <delay.h>

Found using:
diff <(git grep -l '#include <delay.h>' -- src/) <(git grep -l 'get_timer_fsb(\|init_timer(\|udelay(\|mdelay(\|delay(' -- src/) |grep "<"

Change-Id: Id3b79789c66e68aa06c63467f4733adecfee24ec
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60609
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/ec/kontron/kempld/kempld_gpio.c

@@ -2,7 +2,7 @@
 
 #include <stdint.h>
 #include <arch/io.h>
-#include <delay.h>
+
 #include "chip.h"
 #include "kempld.h"
 #include "kempld_internal.h"

src/ec/starlabs/merlin/ec.c

@@ -1,7 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <console/console.h>
-#include <delay.h>
 #include <device/device.h>
 #include <device/pnp.h>
 #include <ec/acpi/ec.h>