clk: qcom: drop the SC7180 Modem subsystem clock driver

clk: qcom: drop the SC7180 Modem subsystem clock driver

This driver has never been used in the DT files merged to the kernel.
According to Sibi, it only worked on the pre-production devices. For the
production devices this functionality has been moved to the firmware.

Drop the driver to remove possible confusion.

Cc: Sibi Sankar <quic_sibis@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240216-drop-sc7180-mss-v1-1-0a8dc8d71c0c@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>