i2c: gpio: OF gpio code does not handle defered probe case
i2c: gpio: OF gpio code does not handle defered probe case

When using device-tree and the i2c-gpio driver is called before the
GPIO node has been probed then it needs to correctly defer the probe
instead of returning a permanent error that the gpio numbers are not
valid.

This fixes the following error:
	/i2c@2: invalid GPIO pins, sda=-517/scl=-517

Signed-off-by: Ben Dooks <0b051c53bf6ec41a37761bf9736dc587af5e4a2e@codethink.co.uk>
Signed-off-by: Wolfram Sang <fd4ce474653598159cad06f3c83387a05cd53a44@the-dreams.de>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs