PSA: Intel xHC driver location moving

[Sam Hansen]

Greetings,

I'm in the process of consolidating some USB drivers.  In particular, the source location of the Intel xHC driver is changing from:

//src/devices/usb/drivers/xhci-rewrite

to:

//src/devices/usb/drivers/xhci

Along with this change, some old legacy code has been removed from the tree.  If you have any out-of-tree work referencing the xhci driver (likely in a board-specific file), you'll want to update your deps to reflect the new location.  The applicable diff would likely look like:

< "//src/devices/usb/drivers/xhci-rewrite:xhci",

> "//src/devices/usb/drivers/xhci",

I've left a stub in .../xhci-rewrite/BUILD.gn which simply aliases to the new driver location.  That stub will be deleted next week.

Apologies for this impacting change.

~sam