add a release note about VirtIO v1 fixes

This explains that we can now run on Q35 chipsets, and that the PR below
has been fixed.

PR:		236922
Reviewed by:	gjb
Differential Revision:	https://reviews.freebsd.org/D29003

website/content/en/releases/13.0R/relnotes.adoc

@@ -291,6 +291,9 @@ The {{< manpage "bhyve" "8">}} utility now supports the VNC server to listen on
 
 In addition to all of these, bhyve received an amount of minor changes, which are too numerous to mention, and which fixes a number of outstanding issues.
 
+Besides the VirtIO changes made for bhyve, there are numerous changes to the {{< manpage "virtio" "4">}} subsystems to make it compatible with the VirtIO V1 spec, which means that FreeBSD can
+now run on the link:https://wiki.qemu.org/images/4/4e/Q35.pdf[Q35 chipset].
+
 [[ports]]
 == Ports Collection and Package Infrastructure