ARM: dts: imx6qdl-apalis: split usdhc1 pinctrl to support 4- and 8-bit

Split the pinctrl property for usdhc1 into a 4-bit SD interface
and an extension to 8-bit. This is required to support both 8-bit
and 4-bit interface on usdhc1 as per the carrier board.

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