greybus: rename interface_block.[c|h] -> interface.[c|h]

Interface_block is being renamed to interface, so move the file first.

Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
diff --git a/drivers/staging/greybus/Makefile b/drivers/staging/greybus/Makefile
index 08cdaf1..6c0b0ca 100644
--- a/drivers/staging/greybus/Makefile
+++ b/drivers/staging/greybus/Makefile
@@ -2,7 +2,7 @@
 		debugfs.o	\
 		ap.o		\
 		manifest.o	\
-		interface_block.o	\
+		interface.o	\
 		bundle.o	\
 		connection.o	\
 		protocol.o	\