ALSA: usb-audio: add dB range mapping for some devices

commit 2d1cb7f658fb9c3ba8f9dab8aca297d4dfdec835 upstream.

Add the correct dB ranges of Bose Companion 5 and Drangonfly DAC 1.2.

Signed-off-by: Yao-Wen Mao <yaowen@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>