Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r265015:
Setting the IMOD value below 0x3F8 can cause IRQ lockups in the Intel
LynxPoint USB 3.0 controllers found in MacBookPro 2013's.

MFC r261872:
Fix minor logical error in the XHCI driver. Set correct SETUP packet
direction value.

MFC r255768:
Stability fixes for Intel LynxPoint XHCI controllers. Disable XHCI port
routing if we get certain errors. Poll for command completion upon
command timeouts. The XHCI error events might not generate interrupts.

PR: usb/181159

MFC r253094:
Use MSI for xhci(4), if supported.

Approved by: re (delphij)

MFC r243780:
- Add support for Etron EJ168 USB 3.0 Host Controllers.
This brand of controllers expects that the number of
contexts specified in the input slot context points
to an active endpoint context, else it refuses to
operate.

- Wrap one or two long lines.

Tested by: Markus Pfeiffer (DragonFlyBSD)

MFC r238551 and r239617:
Add support for Intel Panther/Lynx Point XHCI port routing.

MFC r229086, r228483 and r228640:
Implement better support for USB controller suspend and resume.
Fix some build issues in avr32dci.c

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

- Add support for 64-byte contexts to XHCI driver.
- Remove some dead code.
- Fixed one instance of missing endian conversion.

Approved by: thompsa (mentor)

Commit initial version of new XHCI driver which was written from
scratch. This driver adds support for USB3.0 devices. The XHCI
interface is also backwards compatible to USB2.0 and USB1.0 and will
evntually replace the OHCI/UHCI and EHCI drivers.

There will be follow-up commits during the coming week to link the
driver into the default kernel build and add missing USB3.0
functionality in the USB core. Currently only the driver files are
committed.

Approved by: thompsa (mentor)