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/board/socrates/sdram.c b/board/socrates/sdram.c
index 8eb4f8f..d358a20 100644
--- a/board/socrates/sdram.c
+++ b/board/socrates/sdram.c
@@ -12,6 +12,7 @@
 #include <asm/processor.h>
 #include <asm/mmu.h>
 #include <spd_sdram.h>
+#include <linux/delay.h>
 
 
 #if !defined(CONFIG_SPD_EEPROM)