Yep. The conduit just needs to be connected to the CPC (earth wire) of the cables it is containing.

Does steel conduit have to be earthed?

These must be earthed, if less than 2mm in thickness, so that the short circuit protective device will operate under fault conditions. You may elect to use steel conduit that is earthed, or anaconda earthed with an appropriate earth clip as recommended by the manufacturer.

Can conduit serve as a ground?

The NEC accepted ground path is Conduit. If the wires are in steel conduit, no other ground wire is needed. You might find this link reporting research on the effectiveness of conduit as a ground relieves them if you have concerns.