PCI: qcom-ep: Move enable/disable resources code to common functions

Remove code duplication by moving the code related to enabling/disabling
the resources (PHY, CLK, Reset) to common functions so that they can be
called from multiple places.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
[mani: renamed the functions and reworded the commit message]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>