clk: qcom: Add SDM660 GPU Clock Controller (GPUCC) driver

The GPUCC manages the clocks for the Adreno GPU found on the
SDM630, SDM636, SDM660 SoCs.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Link: https://lore.kernel.org/r/20210113183817.447866-9-angelogioacchino.delregno@somainline.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>