net: ravb: Add R8A77990 E3 compatible

Add new compatible to the Ethernet AVB driver for R8A77990 E3 SoC.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>