gpio: dwapb: Discard ACPI GPIO-chip IRQs request

Since GPIOlib-based IRQ-chip interface is now utilized there is no need
in calling the methods acpi_gpiochip_{request,free}_interrupts() here.
They will be called from gpiochip_add_irqchip()/gpiochip_irqchip_remove()
anyway.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200730152808.2955-8-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>