[qemu] Earlgrey 1.0.0 usb: improve bus reset handling

[pamaury]

Description

Bus resets are currently modelled as zero-time events even though they take 10ms or more on a real bus. This is potentially important because with the current code, it is theoretically possible to receive a reset closely followed by a SETUP. This would lead the driver to set both the reset and setup interrupts simulteanously. The software stack would then be unable to determine the order of the events and be confused.

This is a follow-up improvement to #27895