Port of a Linux commit 2d8ed46

  Add code needed to support i.MX8MQ variant.

  Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
  Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
  Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
  Cc: Bjorn Helgaas <bhelgaas@google.com>
  Cc: Fabio Estevam <fabio.estevam@nxp.com>
  Cc: Chris Healy <cphealy@gmail.com>
  Cc: Lucas Stach <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>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>