reset: uniphier: Add USB glue reset support

reset: uniphier: Add USB glue reset support

Add reset control support in USB glue logic. This needs to control
the external clocks and resets for the logic before accessing the
glue logic.

The USB dm tree when using dwc3-generic is the following:

   USB glue
     +-- controller       (need controller-reset)
     +-- controller-reset (need syscon-reset)
     +-- phy

The controller needs to deassert "controller-reset" in USB glue before
the controller registers are accessed. The glue needs to deassert
"syscon-reset" before the glue registers are accessed.

The glue itself doesn't have "syscon-reset", so the controller-reset
controls "syscon-reset" instead.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: Marek Vasut <marex@denx.de>