clk: clock-local2: Support parsing voter clocks from dt

Voter clocks are a type of cbc which is used by several different hw
execution environments, like TZ, hypervisor, or a remote processor.
A hw based voting mechanism is provided for this clock type.

Change-Id: Ib0aab12ee34c951814ccae25a46c666f85f04f9f
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>