dts: arm: microchip: add dtsi files for Microchip PIC32CX SG SoC series

Adds common and SoC-specific .dtsi files for the Microchip
PIC32CX SG family. These files define core peripherals,
address maps, and interrupt controller structure shared
across the PIC32CX SG variants.

Signed-off-by: Muhammed Asif <muhammed.asif@microchip.com>
13 files changed