..you're probably out of luck. You might get a generic USB print driver to work (the 7440 is a HL-2140 with a scanner and an adf and such so a Solaris driver for that might let you print) but as for the specific functions I doubt its available.
I've gotta ask....why do you need this $150 MFC to work on a god-knows-how-much-it-cost Solaris machine?