ARM: dts: imx6q-apalis-ixora: fix usdhc2 pinctrl property

The SD1 pinctrl-0 property is overridden but only the card detect pin
is muxed, the control and data signals are not referenced at all.
It worked because the bootloader muxed them to a sensible state though.
Fix this.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>