ECSPI chipselect (MX6_PAD_EIM_D19__GPIO3_IO19) is used with GPIO functionality,
so it does not make sense to set its pad as SPI pin.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Eric Nelson <eric.nelson@boundarydevices.com>
Acked-by: Eric Nelson <eric.nelson@boundarydevices.com>