imx: ventana: auto-configure for IMX6Q vs IMX6DL

imx: ventana: auto-configure for IMX6Q vs IMX6DL

use the new iomux function and a macros to create a multi-dimensional array
of iomux values without duplicating the defintions.

Cc: Stefan Roese <sr@denx.de>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Andy Ng <andreas2025@gmail.com>
Cc: Eric Nelson <eric.nelson@boundarydevices.com>
Cc: Tapani Utriainen <tapani@technexion.com>
Cc: Tom Rini <trini@ti.com>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>