i2c: pxa: Return I2C_RETRY when timeout in pio mode

In case of timeout in pio mode of operation return I2C_RETRY.
This behavior will be same as interrupt mode of operation.

Signed-off-by: Shouming Wang <wangshm@marvell.com>
[vaibhav.hiremath@linaro.org: Updated changelog]
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>