FROMGIT: of: property: Add device link support for extcon

Add support for creating device links out of more DT properties.

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Rob Herring <robh@kernel.org>
(cherry picked from commit 78056e701c61132d15e0942e415926a6393fcf17
 git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git

 for-next)
Signed-off-by: Saravana Kannan <saravanak@google.com>
Change-Id: I65ca9efd8d8dde2c366dd7ec99e4e7d03f3735e7