Here is a request for alsa-driver-0.9.4. The old ebuild should work fine although I'm unable to try it on overlay at the moment. Apologies.
It seems alsa-project has updated not only alsa-driver but all alsa packages to version 0.9.4 so I've modified this bug to apply to alsa-driver, alsa-lib, alsa-utils, alsa-tools and alsa-oss since separate bugs did not seem worth it.
Ebuilds for alsa-driver, alsa-lib, alsa-utils, alsa-oss, alsa-tools 0.9.4 are now in the portage tree (~arch masked). Please test. Thanks for the report.