edtlib: allow const arrays

Allow for having array types (array, uint8-array, string-array) be const.
This would allow for something like:

properties:
    reg-names:
        const: ["foo", "bar"]

To be supported.

Renamed function _check_prop_type_and_default to _check_prop_by_type
as part of this change and Moved the check for 'const' types into
_check_prop_by_type as its similar to the prop_type check and it was
easier to implement in _check_prop_by_type as we already extract
prop_type from the option in that function.

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

scripts/dts/python-devicetree/tests/test-bindings/props.yaml

@@ -27,6 +27,7 @@ properties:
 
     string-array:
         type: string-array
+        const: ['foo', 'bar', 'baz']
 
     phandle-ref:
         type: phandle