usb: dwc3: use proper initializers for property entries

We should not be reaching into property entries and initialize them by
hand, but rather use proper initializer macros. This way we can alter
internal representation of property entries with no visible changes to
their users.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>