chrpath.bbclass: fix Darwin support

chrpath.bbclass: fix Darwin support

Ported from the meta-darwin layer:
The call to out.split("\n") expects a string, thus the parameter text=True is
needed (otherwise Popen returns a bytes object).

Note that "text" is just a more readable alias for universal_newlines.

Signed-off-by: Dominik Schnitzer <dominik@snap.com>
Signed-off-by: Etienne Cordonnier <ecordonnier@snap.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>