ALSA: mixart: More constifications

Apply const prefix to each possible place: the string arrays and the
static tables for volumes.

Just for minor optimization and no functional changes.

Link: https://lore.kernel.org/r/20200105144823.29547-25-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/mixart/mixart_hwdep.c

@@ -548,7 +548,7 @@ static int mixart_dsp_load(struct mixart_mgr* mgr, int index, const struct firmw
 
 int snd_mixart_setup_firmware(struct mixart_mgr *mgr)
 {
-	static char *fw_files[3] = {
+	static const char * const fw_files[3] = {
 		"miXart8.xlx", "miXart8.elf", "miXart8AES.xlx"
 	};
 	char path[32];

sound/pci/mixart/mixart_mixer.c

@@ -20,7 +20,7 @@
 #include <sound/tlv.h>
 #include "mixart_mixer.h"
 
-static u32 mixart_analog_level[256] = {
+static const u32 mixart_analog_level[256] = {
 	0xc2c00000,		/* [000] -96.0 dB */
 	0xc2bf0000,		/* [001] -95.5 dB */
 	0xc2be0000,		/* [002] -95.0 dB */
@@ -443,7 +443,7 @@ static const struct snd_kcontrol_new mixart_control_output_switch = {
 	.put =          mixart_audio_sw_put
 };
 
-static u32 mixart_digital_level[256] = {
+static const u32 mixart_digital_level[256] = {
 	0x00000000,		/* [000] = 0.00e+000 = mute if <= -109.5dB */
 	0x366e1c7a,		/* [001] = 3.55e-006 = pow(10.0, 0.05 * -109.0dB) */
 	0x367c3860,		/* [002] = 3.76e-006 = pow(10.0, 0.05 * -108.5dB) */