ARM: dts: imx6q-apalis: Clean-up sd card support

Configure SOM DTSI to 8-bit, card detect in the SoM dtsi as this is
the Apalis family default functionality.
Limit the interface to 4-bit only on the Ixora V1.1 carrier boards.

Signed-off-by: Denys Drozdov <denys.drozdov@toradex.com>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>