Adding fastboot_driver interface + mock

Adding mock fastboot_driver to be used for testing

Test: tested fastboot_test
Bug: 194686221
Change-Id: I6948310d44b75c0f389cbfd194747649aaccb0b8
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index b5033ff..2d79e42 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -29,6 +29,7 @@
 
 #include <string>
 #include "fastboot_driver.h"
+#include "fastboot_driver_interface.h"
 #include "filesystem.h"
 #include "super_flash_helper.h"
 #include "util.h"