usb: dwc2: Add comment about BCM2848 ACPI ID

During recent code review the different naming between ACPI and OF
IDs led to confusion. So add a clarifying comment.

Link: https://lore.kernel.org/linux-usb/38e46b44-6248-45e8-bdf9-66008a2fe290@arm.com/


Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240728130029.78279-4-wahrenst@gmx.net


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>