Unfortunately right now it's impossible SBCL doesn't have a working ARM port. Here is an unfinished attempt by Alastair Bridgewater, but there's still a lot of work to be done to make it work and no one seems to be willing to do it. Maybe I'll take a stab at it someday as I did learn some ARM assembly while porting CLISP, but I don't quite believe in success. Another possibility is to try to port CCL instead, they say this may turn out to be easier...
In addition to patched CLISP, I think it should be possible to get ECL to work under Maemo. It seems that it became relatively modern CL implementaion, but as far as I understand it still has problems with unicode support, and in my case that means a great PITA with cyrillic letters.