greybus: gb-audio: fix build breakage on 4.1-rc1

In commit 1efb53a2 ("ASoC: simple-card: Remove support for setting
differing DAI formats"), the .fmt field was removed from struct
asoc_simple_dai.  Fix this build breakage by not trying to set it.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Acked-by: John Stultz <john.stultz@linaro.org>

drivers/staging/greybus/audio.c

@@ -106,7 +106,9 @@ struct asoc_simple_card_info *setup_card_info(int device_count)
 	obj->card_info.codec		= obj->codec_name;
 	obj->card_info.platform		= obj->platform_name;
 	obj->card_info.cpu_dai.name	= obj->dai_name;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 1, 0)
 	obj->card_info.cpu_dai.fmt	= GB_FMTS;
+#endif
 #if USE_RT5645
 	obj->card_info.daifmt		= GB_FMTS;
 	sprintf(obj->codec_name, "rt5645.%s", "6-001b"); /* XXX do i2c bus addr dynamically */