FROMGIT: pcie: dwc: qcom: Add cfg clock to 2.4.0

Change-Id: I6e227b05c5e69d66f293bee7d08c21220bd7b93e
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
(cherry picked from commit d973772060fecaed460e37772084ed9015a3d24d
https://git.linaro.org/people/niklas.cassel/kernel.git/commit/?h=niklas-qcs404-pcie-4.14

)
Signed-off-by: Prashanth Vadde <pvadde@codeaurora.org>
Reviewed-on: https://chromium-review.googlesource.com/c/1343763


Reviewed-by: Zhihong Yu <zhihongyu@chromium.org>
Tested-by: Zhihong Yu <zhihongyu@chromium.org>