audio: fix audio timer rate conversion bug

audio: fix audio timer rate conversion bug

Currently the default audio timer frequency is 10000Hz instead of
a period of 10000us. Also the audiodev timer-period property gets
converted like a frequency. Only handling of the legacy
QEMU_AUDIO_TIMER_PERIOD environment variable is correct because
it's actually a frequency.

With this patch the property timer-period is really a timer period
and QEMU_AUDIO_TIMER_PERIOD remains a frequency.

Fixes: 71830221fb "-audiodev command line option basic implementation."
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Reviewed-by: Zoltán Kővágó <DirtY.iCE.hu@gmail.com>
Message-id: 90b95e4f-39ef-2b01-da6a-857ebaee1ec5@t-online.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>