ARM: dts: imx6q-evi: support altera-ps-spi

Add support for Altera FPGA connected to an spi port
to the evi devicetree file

Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>