ALSA: hda - Fix path power activation

The widget power-saving code tries to turn up/down the power of each
widget in the I/O paths that are modified at each jack plug/unplug.
The recent report revealed that the power activation leaves some
widgets unpowered after plugging.  This is because
snd_hda_activate_path() turns on path->active flag at the end of the
function while the path power management is done before that.  Then
it's regarded as if nothing is active, and the driver turns off the
power.

The fix is simply to set the flag at the beginning of the function,
before trying to power up.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=102521


Cc: <stable@vger.kernel.org> [v4.1+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>