src/mainboard: 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: I50fcbb16895662c7451fec1569a8a61398792531
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60607
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/mainboard/google/guybrush/variants/baseboard/gpio.c

@@ -4,7 +4,6 @@
 #include <baseboard/gpio.h>
 #include <baseboard/variants.h>
 #include <commonlib/helpers.h>
-#include <delay.h>
 #include <gpio.h>
 #include <soc/gpio.h>
 

src/mainboard/google/octopus/variants/bobba/variant.c

@@ -4,7 +4,6 @@
 #include <boardid.h>
 #include <sar.h>
 #include <baseboard/variants.h>
-#include <delay.h>
 #include <gpio.h>
 #include <ec/google/chromeec/ec.h>
 #include <soc/intel/apollolake/chip.h>

src/mainboard/google/octopus/variants/dood/variant.c

@@ -3,7 +3,6 @@
 #include <acpi/acpi.h>
 #include <sar.h>
 #include <baseboard/variants.h>
-#include <delay.h>
 #include <gpio.h>
 #include <ec/google/chromeec/ec.h>
 #include <soc/intel/apollolake/chip.h>

src/mainboard/google/octopus/variants/garg/variant.c

@@ -5,7 +5,6 @@
 #include <ec/google/chromeec/ec.h>
 #include <drivers/intel/gma/opregion.h>
 #include <baseboard/variants.h>
-#include <delay.h>
 #include <gpio.h>
 #include <variant/sku.h>
 #include <soc/intel/apollolake/chip.h>