dt/bindings: Add bindings for PIC32/MZDA platforms

dt/bindings: Add bindings for PIC32/MZDA platforms

This adds support for the Microchip PIC32 platform along with the
specific variant PIC32MZDA on a PIC32MZDA Starter Kit.

Signed-off-by: Joshua Henderson <[email protected]>
Acked-by: Rob Herring <[email protected]>
Cc: Pawel Moll <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Ian Campbell <[email protected]>
Cc: Kumar Gala <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Patchwork: https://patchwork.linux-mips.org/patch/12096/
Signed-off-by: Ralf Baechle <[email protected]>