clk: qcom: Add support for multiple PLL software instances

There could be use cases where the PLL could support various software
instances for various peripherals or for cpu. In those cases PLL need to
support aggregation logic for the voting and devoting on the PLL.

Change-Id: Ie5148a75452dccc555989a454996b945956f94e5
Signed-off-by: Taniya Das <tdas@codeaurora.org>