Convert CONFIG_SPD_EEPROM to Kconfig

This converts the following to Kconfig:
   CONFIG_SPD_EEPROM

Cc: Stefan Roese <sr@denx.de>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/MPC8548CDS_defconfig b/configs/MPC8548CDS_defconfig
index 2ac4f26..5c83e80 100644
--- a/configs/MPC8548CDS_defconfig
+++ b/configs/MPC8548CDS_defconfig
@@ -44,6 +44,7 @@
 CONFIG_BOOTFILE="8548cds/uImage.uboot"
 CONFIG_USE_ETHPRIME=y
 CONFIG_ETHPRIME="eTSEC0"
+CONFIG_SPD_EEPROM=y
 CONFIG_CHIP_SELECTS_PER_CTRL=2
 CONFIG_DDR_ECC=y
 CONFIG_ECC_INIT_VIA_DDRCONTROLLER=y