pcm: status dump fix timestamp formatting

pcm: status dump fix timestamp formatting

nanosecond part formatted with %06 will give incorrect/confusing results:

trigger_time: 154.9748287
trigger_time: 154.60109090
trigger_time: 154.110425257

time seems to run backwards...

This patch converts to us before printing
which gives the correct/expected result:

trigger_time: 154.009748
trigger_time: 154.060109
trigger_time: 154.110425

Signed-off-by: Andreas Pape <apape@de.adit-jv.com>
Signed-off-by: Mounesh Sutar <sutar.mounesh@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>