DTS property attributes are (by default) not required.
Explicitly specifying `required: false` is redundant.
Perhaps a warning to that effect would be useful.
Signed-off-by: Chris Friedt <cfriedt@meta.com>
In case a "required: False" enum binding doesn't mention a
default value, but a default value makes sense to be set in the code,
DT_ENUM_IDX_OR could be used to provide the default idx to be used.
New macro comes with appropriate tests.
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>