Enable pvscsi and vmx in arm64 GENERIC

FreeBSD pvscsi and vmx work with VMware ESXi Arm "Fling"; provide these
in GENERIC for a convenient out-of-the-box experience.

PR: 253202
Reported by: Vincent Milum Jr
Sponsored by: The FreeBSD Foundation

(cherry picked from commit 375d797b81916eb3d16927c9dac8c42975784252)