dt-bindings: reset: imx7: Document usage on i.MX8MQ SoCs

The driver now supports i.MX8MQ, so update bindings accordingly.

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: linux-imx@nxp.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>