Yes, beginning with the Lattice Diamond 1.2 release, the ispVM System programmer tool supports programming the Lattice MachXO2 device via the Slave SPI port using a standard Lattice Programming cable.
Connect the programming cable to the XO2 SPI pins as follows:
TCK => CCLK
TDI => SISPI
TDO => SPISO
ispEN => SN
VCC => VDD
GND => GND
(Leave all other cable pins unconnected)