common: Drop linux/delay.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/adc/adc-uclass.c b/drivers/adc/adc-uclass.c
index 0a492eb..d435667 100644
--- a/drivers/adc/adc-uclass.c
+++ b/drivers/adc/adc-uclass.c
@@ -12,6 +12,7 @@
 #include <dm/device-internal.h>
 #include <dm/uclass-internal.h>
 #include <adc.h>
+#include <linux/delay.h>
 #include <power/regulator.h>
 
 #define ADC_UCLASS_PLATDATA_SIZE	sizeof(struct adc_uclass_platdata)