APM X-Gene Storm SoC supports 4 serial ports. This patch adds device nodes
for serial ports 1 to 3 (a device node for serial port 0 is already present
in the dts file).
This patch also sets the compatible property of serial nodes to "ns16550a".
Signed-off-by: NVinayak Kale <vkale@apm.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>