The MachXO2 LVDS IOs with 2.5V Vccio supply support 1.8V level input. MachXO2 LVDS IOs are used to catch sensor data for subLVDS To Parallel Sensor Bridge solution.
For more information, refer page 3-9, of DS1035-MachXO2 Datasheet given on this link: https://www.latticesemi.com/view_document?document_id=38834
When you select 2.5V VCCIO, with VCM (Input Common Mode Voltage) in the range from 0.05V to 2.0V, VTHD (Differential Input Voltage Threshold) higher than 100mV, 1.8V differential input signals (VINP, VINM < 2.05V) from the sensor should work with MachXO2 LVDS.