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/ls2080ardb_nand_defconfig b/configs/ls2080ardb_nand_defconfig
index f642fc7..5ce37fd 100644
--- a/configs/ls2080ardb_nand_defconfig
+++ b/configs/ls2080ardb_nand_defconfig
@@ -17,6 +17,7 @@
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT=y
 CONFIG_CMD_GREPENV=y
+CONFIG_CMD_EEPROM=y
 CONFIG_CMD_GPT=y
 CONFIG_CMD_MMC=y
 CONFIG_CMD_I2C=y