Add a sysctl, sysctl hw.snd.report_soft_formats, that controls whether the AIOGCAP ioctl reports software-emulated formats.  It defaults to on.  People who use performance-sensitive audio software and do not want it to pick a software-emulated audio format instead of one supported by their hardware should turn it off.
Add a sysctl, sysctl hw.snd.report_soft_formats, that controls whether the
AIOGCAP ioctl reports software-emulated formats.  It defaults to on.  People
who use performance-sensitive audio software and do not want it to pick a
software-emulated audio format instead of one supported by their hardware
should turn it off.

This unbreaks isdnphone(1) on systems with PCM-only sound cards.

Approved by:	cg

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase