ASoC: Mark WM8958 microphone detection registers readable

So they show up in codec_reg.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm8994-tables.c

@@ -209,9 +209,9 @@ const struct wm8994_access_mask wm8994_access_masks[WM8994_CACHE_SIZE] = {
 	{ 0x0000, 0x0000 }, /* R205 */
 	{ 0x0000, 0x0000 }, /* R206 */
 	{ 0x0000, 0x0000 }, /* R207 */
-	{ 0x0000, 0x0000 }, /* R208 */
-	{ 0x0000, 0x0000 }, /* R209 */
-	{ 0x0000, 0x0000 }, /* R210 */
+	{ 0xFFFF, 0xFFFF }, /* R208 */
+	{ 0xFFFF, 0xFFFF }, /* R209 */
+	{ 0xFFFF, 0xFFFF }, /* R210 */
 	{ 0x0000, 0x0000 }, /* R211 */
 	{ 0x0000, 0x0000 }, /* R212 */
 	{ 0x0000, 0x0000 }, /* R213 */