Tighten up the interface boundaries by adding an extension function
that separates *how* we preprocess the DTS from *what* DTS files we
are preprocessing. This involves a functional change to the pre_dt
module.
This is useful cleanup but is also groundwork for relying on this
helper function when adding system devicetree support.
Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
Create a separate module that sets up all our devicetree handling, by
setting up common variables that would apply to any and all DT
processing. This is then included in the regular dts module that we
include in zephyr_default.cmake.
The separation of this code from dts.cmake is groundwork for enabling
system devicetree in Zephyr, which will need the same definitions
included into its scope.
Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>