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/ti/ks2_evm/board_k2g.c b/board/ti/ks2_evm/board_k2g.c
index a0fd03a..920d0d3 100644
--- a/board/ti/ks2_evm/board_k2g.c
+++ b/board/ti/ks2_evm/board_k2g.c
@@ -6,6 +6,7 @@
  *     Texas Instruments Incorporated, <www.ti.com>
  */
 #include <common.h>
+#include <eeprom.h>
 #include <env.h>
 #include <init.h>
 #include <asm/arch/clock.h>