arm64: dts: ti: k3-am64: Add GPIO DT nodes

Add device tree nodes for GPIO modules and interrupt controller in main
and mcu domains.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210319051950.17549-2-a-govindraju@ti.com