clk: qcom: Add MSM8976/56 Global Clock Controller (GCC) driver

Add support for the global clock controller found on MSM8956
and MSM8976 SoCs.
Since the multimedia clocks are actually in the GCC on these
SoCs, this will allow drivers to probe and control basically
all the required clocks.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Co-developed-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Co-developed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211208091036.132334-3-marijn.suijten@somainline.org