In order to enable supporting i.MX8MQ with this driver, convert it to
expect variant specific bits to be passed via driver data.

Cc: p.zabel@pengutronix.de
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: cphealy@gmail.com
Cc: l.stach@pengutronix.de
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: "A.s. Dong" <aisheng.dong@nxp.com>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: linux-imx@nxp.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>