clk: qcom: Add support for clock dependency

Add clock ops for taking care of a dependent clock when the actual
clock requests are made.

Change-Id: I52691ef9f183da035ddf9c05fb73811f48fef74c
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: David Collins <collinsd@codeaurora.org>