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/stpmic1.c b/drivers/power/regulator/stpmic1.c
index 1e3f96f..3e342f4 100644
--- a/drivers/power/regulator/stpmic1.c
+++ b/drivers/power/regulator/stpmic1.c
@@ -7,6 +7,7 @@
 #include <common.h>
 #include <dm.h>
 #include <errno.h>
+#include <linux/delay.h>
 #include <power/pmic.h>
 #include <power/regulator.h>
 #include <power/stpmic1.h>