4 - compatible : should be "opencores,tiny-spi-rtlsvn2".
5 - gpios : should specify GPIOs used for chipselect.
7 - clock-frequency : input clock frequency to the core.
8 - baud-width: width, in bits, of the programmable divider used to scale
9 the input clock to SCLK.
11 The clock-frequency and baud-width properties are needed only if the divider
12 is programmable. They are not needed if the divider is fixed.