Call path:

  1) snd_hdac_power_up_pm()
  2) snd_hdac_power_up()
  3) pm_runtime_get_sync()
  4) __pm_runtime_resume()
  5) rpm_resume()

The rpm_resume() returns 1 when the device is already active.
Because the return value is unmodified, the hdac regmap read/write
functions should allow this value for the retry I/O operation, too.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>