of_parse_phandle() returns NULL either if the property name
itself does not exist or if it (exists and) does not
reference a valid phandle.
Giving out a warn like the one below (that the property references
an invalid phandle) can be confusing when the property itself
does not exist in the node.
Fix it with a more sensible message and make it a dev_dbg instead
of a dev_warn.
Reported-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>