Switch the driver from legacy gpio API that is deprecated to the newer
gpiod API that respects line polarities described in ACPI/DT.

Note that because existing DTSes specify incorrect polarity of reset
lines (active high) and GPU drivers have adopted to this, we follow
the suit and use inverted values when controlling reset lines.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>