ARM: kirkwood: Add i2c alias so setting bus number

When using platform_driver instantiation, the i2c bus was given bus
number 0. The kirkwood-t5325 audio driver has this bus number hard
coded for the address of the codec. However by default device tree i2c
busses are dynamically allocated a bus number, starting from 1. Thus
the kirkwood-t5325 cannot find its audio codec. By adding an alias in
the DT file we can control the bus number and set it to 0. The codec
can then be found.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>