Fastboot: fix fastboot timeout issue of Windows host side

Normally fastboot follows the procedure that host sends a command
to device and device sends back response after the command
is executed.

But sometimes device spends too long time to execute the command
so that timeout error occurs before host receives the response.

This patch fixes the issue by aligning with the solution of ADB.
ADB commit id: 1c4b760a

Change-Id: I50e6bf428ea38219b64cca6ab82db22af28e0264
Author: Jiebing Li <jiebing.li@intel.com>
Signed-off-by: Bo Huang <bo.b.huang@intel.com>