greybus: include "gpbridge.h" from "greybus.h"

Avoid the need for all the source files to include "gpbridge.h"
by just having "greybus.h" include it.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/drivers/staging/greybus/audio-pcm.c b/drivers/staging/greybus/audio-pcm.c
index b327008..a1faf78 100644
--- a/drivers/staging/greybus/audio-pcm.c
+++ b/drivers/staging/greybus/audio-pcm.c
@@ -11,8 +11,8 @@
 #include <sound/soc.h>
 #include <sound/dmaengine_pcm.h>
 #include <sound/simple_card.h>
+
 #include "greybus.h"
-#include "gpbridge.h"
 #include "audio.h"
 
 /*