PCI: qcom: Remove MSI-X Capability for Root Ports

PCI: qcom: Remove MSI-X Capability for Root Ports

On some platforms like Glymur, the hardware does not support MSI-X in RC
mode, yet still exposes the MSI-X capability. However, it omits the
required MSI-X Table and PBA structures.

This mismatch can lead to issues where the PCIe port driver requests MSI-X
instead of MSI, causing the Root Port to trigger interrupts by writing to
an uninitialized address, resulting in SMMU faults.

To address this, remove MSI-X capability unconditionally for Root Ports of
all SoCs as none of the Qcom PCIe Root Ports support MSI-X.

Signed-off-by: Qiang Yu <qiang.yu@oss.qualcomm.com>
[mani: updated description]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251109-remove_cap-v1-4-2208f46f4dc2@oss.qualcomm.com