nvmem: imx-ocotp: reset error status on probe

If software running before the OCOTP driver is loaded left the
controller with the error status pending, the driver will never
be able to complete the read timing setup. Reset the error status
on probe to make sure the controller is in usable state.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>