ASoC: tas2781: mark dvc_tlv with __maybe_unused

BugLink: https://bugs.launchpad.net/bugs/2097393

[ Upstream commit 831ec5e ]

Since we put dvc_tlv static variable to a header file it's copied to
each module that includes the header. But not all of them are actually
used it.

Fix this W=1 build warning:

include/sound/tas2781-tlv.h:18:35: warning: 'dvc_tlv' defined but not
used [-Wunused-const-variable=]

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: ae065d0 ("ALSA: hda/tas2781: remove digital gain kcontrol")
Signed-off-by: Gergo Koteles <[email protected]>
Message-ID: <0e461545a2a6e9b6152985143e50526322e5f76b.1711665731.git.soyer@irl.hu>
Signed-off-by: Takashi Iwai <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Manuel Diewald <[email protected]>
Signed-off-by: Koichiro Den <[email protected]>

Author: soyersoyer

include/sound/tas2781-tlv.h

@@ -15,7 +15,7 @@
 #ifndef __TAS2781_TLV_H__
 #define __TAS2781_TLV_H__
 
-static const DECLARE_TLV_DB_SCALE(dvc_tlv, -10000, 100, 0);
+static const __maybe_unused DECLARE_TLV_DB_SCALE(dvc_tlv, -10000, 100, 0);
 static const DECLARE_TLV_DB_SCALE(amp_vol_tlv, 1100, 50, 0);
 
 #endif