Move the RX (MISO) delaying capability information to Devicetree. It is
done using 2 properties:
- rx-delay-supported: enabled on SPI nodes that support delaying RX.
This property can be used by the driver to determine if this
capability is supported or not on a given instance.
- rx-delay: the actual RX delay value
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>