misc: Kconfig: Add SPL_I2C_EEPROM option

This option is an SPL-variant of the I2C_EEPROM option to enable
the driver for generic I2C-attached EEPROMs for SPL.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>