When HP laptops with mute and mic-record LEDs go to runtime suspend,
these LEDs are turned on forcibly no matter whether GPIO pis are on or
off.  This strange behavior seems triggered by resetting the HD-audio
bus link at azx_rutime_suspend().  So, just add a new hda_bus flag to
avoid the link reset at runtime suspend and set it for these HP
machines.

Signed-off-by: Takashi Iwai <tiwai@suse.de>