ARC: [plat-hsdk] Enable DW APB GPIO support

Enable GPIO support on HSDK. HSDK SoC includes Synopsys
DesignWare DW_apb_gpio IP with 24 GPIOs mapped onto port A.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>