clk: qcom: Add display clock driver for SM6150

Add support for display clock controller found on SM6150
based devices. This would allow display device driver
to probe and control their clocks.

Change-Id: I2e5e20f5bf518d6bc1128b6c2fb26a5e0480a4a3
Signed-off-by: Veera Vegivada <vvegivad@codeaurora.org>