There is currently no way to tie an sonar analysis to a save action.
However, you do not need to run the maven based analysis. Assuming you use a recent version of SonarQube and SonarQube ide (4+ and 3.3), you can simply run the analysis using the shortcut (ALT-Ctrl-Q, by default).
Using incremental mode with SonarQube 4+, this is actually really fast, because it analyzes only the changed files as compared to the last successful SonarQube run.
Of course, you need make sure that your buildserver regularily runs your full SonarQube builds as well.