common: Move old EEPROM functions into a new header

These functions do not use driver model but are still used. Move them to a
new eeprom.h header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/dhelectronics/dh_imx6/dh_imx6.c b/board/dhelectronics/dh_imx6/dh_imx6.c
index 037be01..33ce7e8 100644
--- a/board/dhelectronics/dh_imx6/dh_imx6.c
+++ b/board/dhelectronics/dh_imx6/dh_imx6.c
@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <eeprom.h>
 #include <init.h>
 #include <dm/device-internal.h>
 #include <asm/arch/clock.h>