usb: misc: Diag_bridge: add INT IN pipe support for rx data path

Product ID 0x90A0 requires to support INT IN pipe support
instead of BULK IN over rx data path.
Add a new count: drop_count.

Change-Id: I45c76ab4537573bfe3fbaa1d56227883be1ab0f3
Signed-off-by: Guang Jian Zeng <gzeng@codeaurora.org>