libusbdrivers: Use delay function from libplatsupport.

libusbdrivers: Remove duplicated aborts.

libusbdrivers: Added comments and references to the driver files.

libusbdrivers: Move various functions to other libraries.

libusbdrivers: Move synchronization structure to libplatsupport.

libusbdrivers: Add licence headers.

libusbdrivers: Replace all assertions and debug macros with ZF_LOG.

libusbdrivers: Cleanup code.

libusbdrivers: Rewrite periodic schedule.

libusbdrivers: Implement proper periodic schedule with respect to the polling
rate.

libusbdrivers: zero the allocated memory for host controller data.

libusbdrivers: Use less ambiguous locking interface.

libusbdrivers: Remove unused code.

libusbdrivers: Remove queue head for async schedule.

libusbdrivers: Added mutex functions to the APIs.

libusbdrivers: Add a lock for each queue head.

libusbdrivers: Free the processed TDs by IOC.

libusbdrivers: Remove processed TDs from the async queue.

libusbdrivers: Move callback function to TD.

libusbdrivers: Move some functions to the appropriate files.

libusbdrivers: Bugfix, break the loop when an empty slot is found.

libusbdrivers: Calculate data toggle bit for control endpoints.

libusbdrivers: Removed deprecated code.

libusbdrivers: Bug fix where inserting new queue head to async schedule.

libusbdriver: Refactor periodic schedule.

libusbdrivers: Bugfix, write to the link pointer register at once.

libusbdrivers: Add function to update the queue head.

libusbdrivers: Change APIs, introduce the endpoint structure.

libusbdrivers: Add support for x86.

libusbdrivers: Fix bug where don't share share the same queue head when plugin
new device.

libusbdrivers: Bugfix, append new queue head to the current async queue.

libusbdrivers: Bugfix, update max packet size and address after initial query.

libusbdrivers: Point TD overlay to the first TD.

libusbdrivers: Add new scheduling function.

libusbdrivers: Update queue head and schedule the queue.

libusbdrivers: Add new xact scheduling functions.

libusbdrivers: Split the host driver into multiple files.