clk: qcom: clk-cpu-osm: Rework the OPP table filling logic

Add support to allow filling the L3 clock OPP tables for more
than one device.
Additionally, merge the l3-dev0 and l3-dev4 properties to
l3_devs.

Change-Id: Id6ef4164f1f9efb399c43222c1126718f5358e61
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>