gpio: fix memory and reference leaks in gpiochip_add error path

Memory allocated and references taken by of_gpiochip_add and
acpi_gpiochip_add were never released on errors in gpiochip_add (e.g.
failure to find free gpio range).

Fixes: 391c970c ("of/gpio: add default of_xlate function if device
has a node pointer")
Fixes: 664e3e5a ("gpio / ACPI: register to ACPI events
automatically")
Cc: stable <stable@vger.kernel.org>

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>