pinctrl: Remove .owner field

platform_driver does not need to set the owner field, as it will be
populated by the driver core, so just remove it.

The semantic patch that makes this change is available
in scripts/coccinelle/api/platform_no_drv_owner.cocci.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>