media: em28xx: fix input name for Terratec AV 350

BugLink: https://bugs.launchpad.net/bugs/1810947

commit 15644bfa upstream.

Instead of using a register value, use an AMUX name, as otherwise
VIDIOC_G_AUDIO would fail.

Cc: stable@vger.kernel.org
Fixes: 766ed64d ("V4L/DVB (11827): Add support for Terratec Grabster AV350")
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/media/usb/em28xx/em28xx-cards.c

@@ -2021,13 +2021,13 @@ struct em28xx_board em28xx_boards[] = {
 		.input           = { {
 			.type     = EM28XX_VMUX_COMPOSITE1,
 			.vmux     = TVP5150_COMPOSITE1,
-			.amux     = EM28XX_AUDIO_SRC_LINE,
+			.amux     = EM28XX_AMUX_LINE_IN,
 			.gpio     = terratec_av350_unmute_gpio,
 
 		}, {
 			.type     = EM28XX_VMUX_SVIDEO,
 			.vmux     = TVP5150_SVIDEO,
-			.amux     = EM28XX_AUDIO_SRC_LINE,
+			.amux     = EM28XX_AMUX_LINE_IN,
 			.gpio     = terratec_av350_unmute_gpio,
 		} },
 	},