FROMGIT: pci: dwc: qcom: Make non-existing clocks optional

The axi_m_vmid, axi_s_xpu and parf clocks are
secure clocks on some platforms and as they are
never toggled by the driver we can omit them.

Change-Id: I8a0530ad30c48f8ee9b1fd875889cfdbd9b06551
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
(cherry picked from commit 101ad0cf073a95a2fac35277587c22de5aef8d99
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/1343764


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