MAINTAINERS: Add Focusrite Scarlett Gen 2/3 Mixer Driver entry

Add Focusrite Scarlett Gen 2/3 Mixer Driver entry.
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/20210622171724.GA15534@m.b4.vuSigned-off-by: Takashi Iwai <tiwai@suse.de>

MAINTAINERS

@@ -7103,6 +7103,13 @@ L:	linux-input@vger.kernel.org
 S:	Maintained
 F:	drivers/input/joystick/fsia6b.c
 
+FOCUSRITE SCARLETT GEN 2/3 MIXER DRIVER
+M:	Geoffrey D. Bennett <g@b4.vu>
+L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
+S:	Maintained
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git
+F:	sound/usb/mixer_scarlett_gen2.c
+
 FORCEDETH GIGABIT ETHERNET DRIVER
 M:	Rain River <rain.1986.08.12@gmail.com>
 M:	Zhu Yanjun <zyjzyj2000@gmail.com>