usb: dfu: f_dfu: Provide infrastructure to adjust DFU's Poll Timeout value

It is necessary to deter the host from sending subsequent DFU_GETSTATUS
request in the case of e.g. writing the buffer to medium.

Here the timeout is increased when we fill up the whole buffer. This delay
allows eMMC memory to perform its internal operations.
Otherwise we end up with HOST's error regarding GET_STATUS receive timeout.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
diff --git a/drivers/usb/gadget/f_dfu.h b/drivers/usb/gadget/f_dfu.h
index cc2c455..0c29954 100644
--- a/drivers/usb/gadget/f_dfu.h
+++ b/drivers/usb/gadget/f_dfu.h
@@ -82,4 +82,6 @@
 	__le16				wTransferSize;
 	__le16				bcdDFUVersion;
 } __packed;
+
+#define DFU_POLL_TIMEOUT_MASK           (0xFFFFFFUL)
 #endif /* __F_DFU_H_ */