MIPS: pic32mzda: Add initial PIC32MZDA Starter Kit defconfig

This adds an initial default config that enables all available PIC32
drivers and is enough for booting a PIC32MZDA Starter Kit.

Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12105/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>