For processing the firmware handling properly for built-in kernels,
implement an asynchronous firmware loading with
request_firmware_nowait().  This means that the codec probing is
deferred when the patch option is specified.
Tested-by: NThierry Reding <thierry.reding@avionic-design.de>
Reviewed-by: NDavid Henningsson <david.henningsson@canonical.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>