https://docs.particle.io/reference/firmware/photon/#spi
When you know that SPI MOSI means Master Out Slave In you can probably guess that this would make most sense to be connected to Data.
Similarly since SCK stands for SPI ClocK it's an easy guess too.
Next obvious choice would be SS meaning Slave Select while CS means Chip Select and hence they seem to match quite nicely.
So you are now left with DC & RST and since these are not SPI specific, you can choose whatever pin you have free.
BTW, there was another thread down a very similar request you might want to look into
Also mentioned in that thread, you can have multiple devices on the same SPI port.
It's easiest when all devices share the same SPI mode, but that's not compulsory.