soc: bcm2835: Add notify xHCI reset property

The property is needed in order to trigger VL805's firmware load. Note
that gap between the property introduced and the previous one is due to
the properties not being defined.

Link: https://lore.kernel.org/r/20200505161318.26200-2-nsaenzjulienne@suse.de
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>