bhyve: Do not panic on invalid input in HDA emulation

The emulated HDA controller passed values taken from guest registers and
from guest memory straight into assert(), so a guest could abort bhyve
with values the emulation did not expect. Reject them instead.

In case the guest asked to start something and it failed, clear the
corresponding run/enable bit.

PR: 256379, 256381, 256382, 256383, 256384, 256385, 256386, 256498
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Reviewed by: bnovkov, jhb
Differential Revision: https://reviews.freebsd.org/D59082

(cherry picked from commit f4d953bea74091874f019e3a2c4902dd013ee739)