AZX_DCAPS_RIRB_DELAY is dedicated only for Nvidia and its purpose is
just to set a flag in bus.  So it's better to be set in the toplevel
driver, either hda_intel.c or hda_tegra.c, instead of the common
hda_controller.c.  This also allows us to strip this flag from dcaps,
so save one more bit there.
Signed-off-by: Takashi Iwai <tiwai@suse.de>