ti: i2c: fix probe_chip() return value

Per documentation, dm_i2c_ops.probe_chip() shall return -EREMOTEIO if
probe fails.

Currently, omap_i2c_probe_chip() returns 1 instead. Fix that.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Heiko Schocher <hs@denx.de>