i3c: Generate aliases for i3c modules

This part was missing, thus preventing user space from loading modules
automatically when MODALIAS uevents are received.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Link: https://lore.kernel.org/linux-i3c/79687073b915182e06fccfb18adcedfd0fadbc99.1582796652.git.vitor.soares@synopsys.com