ASoC: Remove unused extern declarations for sh4_hac_dai and sh7760_soc_platform

Both sh4_hac_dai and sh7760_soc_platform are changed to static
by multi-component patch and they are not used in sh7760-ac97.c now.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/sh/sh7760-ac97.c

@@ -16,10 +16,6 @@
 
 #define IPSEL 0xFE400034
 
-/* platform specific structs can be declared here */
-extern struct snd_soc_dai_driver sh4_hac_dai[2];
-extern struct snd_soc_platform_driver sh7760_soc_platform;
-
 static struct snd_soc_dai_link sh7760_ac97_dai = {
 	.name = "AC97",
 	.stream_name = "AC97 HiFi",