PCI: qcom: Fix the fixup of PCI_VENDOR_ID_QCOM

There exists non-bridge PCIe devices with PCI_VENDOR_ID_QCOM, so limit
the fixup to only affect the relevant PCIe bridges.

Fixes: 322f0343 ("PCI: qcom: Use default config space read function")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Cc: stable@vger.kernel.org # v5.2+