Move common properties like 'compatible', 'reg', 'reg-names',
'interrupts', 'interrupt-names', and 'label' into one common base.yaml
that all the other yaml's can inherit from. This removes both
duplication and inconsistent definition.
The device specific yamls just need to say if a property is 'required'
or not.
NOTE: due to some generation conflicts we did not covert
'soc-nv-flash.yaml' to use base.yaml.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>