clk: qcom: Add support for AOP clock controller

The Always On Processor(AOP) supports enabling, disabling and
scaling few shared clocks using the QMP mailbox client. Add
support for the same to register the QDSS clocks with AOP.

Change-Id: I31dd297acf639640a410494ad4dd96caa76a873f
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>