dt-bindings: usb: generic-ehci: Add Allwinner D1 compatible

The Allwinner D1 contains USB controllers which claim to be compatible
with the EHCI specification version 1.0.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220702195249.54160-3-samuel@sholland.org