mips: dts: mscc: enable spi and NOR flash support on ocelot PCB123

Ocelot PCB123 has a SPI NOR connected on its SPI bus.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20103/
Cc: Mark Brown <broonie@kernel.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Allan Nielsen <allan.nielsen@microsemi.com>