PCI: qcom: Remove redundancy between qcom_pcie and qcom_pcie_cfg

In preparation to adding more flags to configuration data, use pointer
to struct qcom_pcie_cfg directly inside struct qcom_pcie, rather than
duplicating all its fields. This would save us from the boilerplate code
that just copies flag values from one struct to another one.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>