clk: qcom: Add modem clock controller driver for SC7180

Add support for the modem clock controller found on SC7180
based devices. This would allow modem drivers to probe and
control their clocks.

Signed-off-by: Taniya Das <tdas@codeaurora.org>
Link: https://lkml.kernel.org/r/1584596131-22741-4-git-send-email-tdas@codeaurora.org


Tested-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>