powerpc/5200: add lite5200 onboard I2C eeprom and flash

Add dts descriptions for onboard 256 byte I2C eeprom (pcf8582C-2)
and 16MB NOR flash (am29lv652d).

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
[grant.likely@secretlab.ca: added lite5200b eeprom and declared lite5200 gpios]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>