You mean you want to recompile it from source? I am not sure what you want since I think those who are able to install SDK and recompile it should have no problem with applying a patch. Anyway It is patch -p1 <path/to/patchfile when run from toplevel scummvm source directory, patch is inside backend/platform/maemo/ (typing from memory). It is also described in the README in toplevel directory.

BTW, got the device yesterday and getting familiar with it now. Everything works fine so far, I'm happy I haven't got a lemon.