ALSA: hda/tas2781: Fix the symbol was not declare warning reported by kernel test robot

After commit 28a09d9 ("ALSA: hda/tas2781: Create an independent lib
to save the shared parts for both SPI and I2C driver") created a separated
lib for both hda-i2c and hda-spi driver, which caused this issue.
sparse warnings: (new ones prefixed by >>)
>> sound/pci/hda/tas2781_hda_spi.c:496:25: sparse: sparse: symbol
   'tas2781_snd_ctls' was not declared. Should it be static?
>> sound/pci/hda/tas2781_hda_spi.c:505:25: sparse: sparse: symbol
   'tas2781_prof_ctl' was not declared. Should it be static?
>> sound/pci/hda/tas2781_hda_spi.c:512:25: sparse: sparse: symbol
   'tas2781_dsp_ctls' was not declared. Should it be static?

Fixes: 28a09d9 ("ALSA: hda/tas2781: Create an independent lib to save the shared parts for both SPI and I2C driver")
Reported-by: kernel test robot <[email protected]>
Closes: https://urldefense.com/v3/__https://lore.kernel.org/oe-kbuild-all/[email protected]/__;!!G3vK!URphGMMfZ2erCLfJdETofl0O1mTSydDLLJ6inMIYWYUDUKYef_IuLvI7pnYj3Mx-4LRIi4BJEw$
Signed-off-by: Shenghao Ding <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>

Author: Shenghao-Ding

sound/pci/hda/tas2781_hda_spi.c

@@ -493,7 +493,7 @@ static int tas2781_force_fwload_put(struct snd_kcontrol *kcontrol,
 	return change;
 }
 
-struct snd_kcontrol_new tas2781_snd_ctls[] = {
+static struct snd_kcontrol_new tas2781_snd_ctls[] = {
 	ACARD_SINGLE_RANGE_EXT_TLV(NULL, TAS2781_AMP_LEVEL, 1, 0, 20, 0,
 		tas2781_amp_getvol, tas2781_amp_putvol, amp_vol_tlv),
 	ACARD_SINGLE_RANGE_EXT_TLV(NULL, TAS2781_DVC_LVL, 0, 0, 200, 1,
@@ -502,14 +502,14 @@ struct snd_kcontrol_new tas2781_snd_ctls[] = {
 		tas2781_force_fwload_put),
 };
 
-struct snd_kcontrol_new tas2781_prof_ctl = {
+static struct snd_kcontrol_new tas2781_prof_ctl = {
 	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
 	.info = tasdevice_info_profile,
 	.get = tasdevice_get_profile_id,
 	.put = tasdevice_set_profile_id,
 };
 
-struct snd_kcontrol_new tas2781_dsp_ctls[] = {
+static struct snd_kcontrol_new tas2781_dsp_ctls[] = {
 	/* Speaker Program */
 	{
 		.iface = SNDRV_CTL_ELEM_IFACE_CARD,