pinctrl: imx: Inline struct imx_pinctrl_soc_info access into probe

pinctrl: imx: Inline struct imx_pinctrl_soc_info access into probe

The probe function is identical across all the pinctrl drivers.
Inline the imx_pinctrl_soc_info access into imx_pinctrl_probe()
and drop all the duplicate probe functions. No functional change.

Signed-off-by: Marek Vasut <marex@denx.de>