spi: cadence_spi: Sync DT bindings with Linux

spi: cadence_spi: Sync DT bindings with Linux

Adopt the Linux DT bindings. This also fixes an issue
with the indaddrtrig register on the Cadence QSPI
device being programmed with the wrong value for the
socfpga arch.

Tested on TI K2G platform:
Tested-by: Vignesh R <[email protected]>
Tested on a socfpga-cyclonev board:
Tested-by: Simon Goldschmidt <[email protected]>
Signed-off-by: Jason Rush <[email protected]>
Reviewed-by: Jagan Teki <[email protected]>
Acked-by: Simon Goldschmidt <[email protected]>
Acked-by: Marek Vasut <[email protected]>