ARM: dts: msm: fix panel supply entry config name for MSM8996

The two panel supply configuration entries for the panels with
and without LAB/IBB have the same device node name. Fix this by
having unique device node names.

Change-Id: I45db7c2dc0a87d295bc9c59d52a2b2d07c74c876
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>