[POWERPC] 4xx: Remove "i2c" and "xxmii-interface" device_types from dts

Remove all "i2c" and "xxmii-interface" (rgmii etc) device_type entries
from the 4xx dts files.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>