clk: qcom: sm6115: Select QCOM_GDSC

While working on the Fxtec Pro1X device, this error shows up with
my own minimal configuration:

gcc-sm6115: probe of 1400000.clock-controller failed with error -38

The clock driver depends on CONFIG_QCOM_GDSC and after enabling
that, the driver probes successfully.

Signed-off-by: Dang Huynh <danct12@riseup.net>
Fixes: cbe63bfd ("clk: qcom: Add Global Clock controller (GCC)
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220910170207.1592220-1-danct12@riseup.net