i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>
bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>
i2c: bcm2835: make driver available on ARCH_BCM2708

Make this driver available on ARCH_BCM2708

Signed-off-by: Noralf Tronnes <notro@tronnes.org>
Merge pull request #651 from notro/i2c

i2c: bcm2708: add device tree support