ASoC: ak4641: Move register defines to main source

The ak4641 driver only has a few register defines. As they are only used in
the one main driver file there is not really a need to keep them in a
separate header.

Moving them to the main source file allows to remove the now empty header
file completely.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/ak4641.c b/sound/soc/codecs/ak4641.c
index c91717d..ebdaf56 100644
--- a/sound/soc/codecs/ak4641.c
+++ b/sound/soc/codecs/ak4641.c
@@ -27,7 +27,27 @@
 #include <sound/tlv.h>
 #include <sound/ak4641.h>
 
-#include "ak4641.h"
+/* AK4641 register space */
+#define AK4641_PM1		0x00
+#define AK4641_PM2		0x01
+#define AK4641_SIG1		0x02
+#define AK4641_SIG2		0x03
+#define AK4641_MODE1		0x04
+#define AK4641_MODE2		0x05
+#define AK4641_DAC		0x06
+#define AK4641_MIC		0x07
+#define AK4641_TIMER		0x08
+#define AK4641_ALC1		0x09
+#define AK4641_ALC2		0x0a
+#define AK4641_PGA		0x0b
+#define AK4641_LATT		0x0c
+#define AK4641_RATT		0x0d
+#define AK4641_VOL		0x0e
+#define AK4641_STATUS		0x0f
+#define AK4641_EQLO		0x10
+#define AK4641_EQMID		0x11
+#define AK4641_EQHI		0x12
+#define AK4641_BTIF		0x13
 
 /* codec private data */
 struct ak4641_priv {