PCI: qcom: Add SM8250 SoC support

The PCIe IP (rev 1.9.0) on SM8250 SoC is similar to the one used on
SDM845. Hence the support is added reusing the members of ops_2_7_0.
The key difference between ops_2_7_0 and ops_1_9_0 is the config_sid
callback, which will be added in successive commit.

Link: https://lore.kernel.org/r/20201208121402.178011-3-mani@kernel.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>