ARM: dts: bcm2711: Add BCM2711 xHCI support

ARM: dts: bcm2711: Add BCM2711 xHCI support

The BCM2711 SoC also has a mostly generic xHCI. The USB port is
currently only usable on the Compute Module 4 (e.g. via IO board).
Because DWC2 and xHCI share the same PHY, we let the bootloader
enable it on demand.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20231205200531.8232-4-wahrenst@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>