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/cmd/i2c.c b/cmd/i2c.c
index a51f781..cc01119 100644
--- a/cmd/i2c.c
+++ b/cmd/i2c.c
@@ -77,6 +77,7 @@
 #include <malloc.h>
 #include <asm/byteorder.h>
 #include <linux/compiler.h>
+#include <linux/delay.h>
 #include <u-boot/crc.h>
 
 /* Display values from last command.