ARC: [plat-hsdk]: Configure APB GPIO controller on ARC HSDK platform

In case of HSDK we have intermediate INTC in for of DW APB GPIO controller
which is used as a de-bounce logic for interrupt wires that come from
outside the board.

We cannot use existing "irq-dw-apb-ictl" driver here because all input
lines are routed to corresponding output lines but not muxed into one
line (this is configured in RTL and we cannot change this in software).

But even if we add such a feature to "irq-dw-apb-ictl" driver that won't
benefit us as higher-level INTC (in case of HSDK it is IDU) anyways has
per-input control so adding fully-controller intermediate INTC will only
bring some overhead on interrupt processing but no other benefits.

Thus we just do one-time configuration of DW APB GPIO controller and
forget about it.

Based on implementation available on arch/arc/plat-axs10x/axs10x.c file.

Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>