Convert CONFIG_CMD_EEPROM et al to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_EEPROM
   CONFIG_CMD_EEPROM_LAYOUT
   CONFIG_EEPROM_LAYOUT_HELP_STRING

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
[trini: Rework Kconfig logic slightly, define EEPROM location on TI eval
platforms]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/C29XPCIE_NAND_defconfig b/configs/C29XPCIE_NAND_defconfig
index 88964b3..42f085a 100644
--- a/configs/C29XPCIE_NAND_defconfig
+++ b/configs/C29XPCIE_NAND_defconfig
@@ -20,6 +20,7 @@
 CONFIG_TPL_I2C_SUPPORT=y
 CONFIG_TPL_MPC8XXX_INIT_DDR_SUPPORT=y
 CONFIG_HUSH_PARSER=y
+CONFIG_CMD_EEPROM=y
 CONFIG_CMD_SF=y
 CONFIG_CMD_I2C=y
 CONFIG_CMD_MII=y