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/power/regulator/regulator-uclass.c b/drivers/power/regulator/regulator-uclass.c
index b959c46..7dcb317 100644
--- a/drivers/power/regulator/regulator-uclass.c
+++ b/drivers/power/regulator/regulator-uclass.c
@@ -9,6 +9,7 @@
 #include <dm.h>
 #include <log.h>
 #include <dm/uclass-internal.h>
+#include <linux/delay.h>
 #include <power/pmic.h>
 #include <power/regulator.h>