USB: ehci-platform: Add ACPI bindings for the EHCI platform driver.

This enables USB on the ARM juno board when booted with
an ACPI kernel. The PNP id comes from the PNP/ACPI registry
and describes an EHCI controller without debug.

Tested-by: Huang Shijie <shijie.huang@arm.com>
Reviewed-by: Graeme Gregory <graeme.gregory@linaro.org>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>