of: add optional options parameter to of_find_node_by_path()
Update of_find_node_by_path():
1) Rename function to of_find_node_opts_by_path(), adding an optional
pointer argument. Provide a static inline wrapper version of
of_find_node_by_path() which calls the new function with NULL as
the optional argument.
2) Ignore any part of the path beyond and including the ':' separator.
3) Set the new provided pointer argument to the beginning of the string
following the ':' separator.
4: Add tests.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Grant Likely <grant.likely@linaro.org>