powerpc/fsl: update compatiable on fsl 16550 uart nodes

The Freescale serial port's are pretty much a 16550, however there are
some FSL specific bugs and features. Add a "fsl,ns16550" compatiable
string to allow code to handle those FSL specific issues.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

powerpc/85xx: create dts components to build up an SoC

Introduce some common components that we can utilize to build up the
various PQ3/85xx device trees.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>