I2C: OMAP: Handle error check for pm runtime

If PM runtime get_sync fails return with the error
so that no further reads/writes goes through the interface.
This will avoid possible abort. Add a error message in case
of failure with the cause of the failure.

Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>