ARC: HSDK: improve reset driver

As for today HSDK reset driver implements only .reset() callback.

In case of driver which implements one of standard
reset controller usage pattern
(call *_deassert() in probe(), call *_assert() in remove())
that leads to inoperability of this reset driver.

Improve HSDK reset driver by calling .reset() callback inside of
.deassert() callback to avoid each reset controller
user adaptation for work with both reset methods
(reset() and {.assert() & .deassert()} pair)

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>