bblayers/makesetup: include local repository paths in discovered layer repo data

bblayers/makesetup: include local repository paths in discovered layer repo data

This can be useful when the caller needs to know where the repos actually
are on local disk (for example to make a local copy of them or obtain
additional information about them).

This field however should be removed from the json output in oe-setup-layers
plugin, as it is host-specific and not part of the schema.

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>