app: fastboot: Move the reponse size macro

Move the usb response size macro to fastboot header file.

Change-Id: I28aec79b37be5dc912db3b1a9040ad6956eafd30
diff --git a/app/aboot/fastboot.c b/app/aboot/fastboot.c
index 5b9dc9a..262a08e 100644
--- a/app/aboot/fastboot.c
+++ b/app/aboot/fastboot.c
@@ -35,8 +35,8 @@
 #include <kernel/thread.h>
 #include <kernel/event.h>
 #include <dev/udc.h>
+#include "fastboot.h"
 
-#define MAX_RSP_SIZE 64
 #define MAX_USBFS_BULK_SIZE (32 * 1024)
 
 void boot_linux(void *bootimg, unsigned sz);