phy: phy-spear1340-miphy: Use module_platform_driver to register driver.

Using the module_platform_driver macro to register the driver as this gets
rid of a lot of the boilerplate code.

Also remove .owner field as this gets overridden in __platform_driver_register.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>