Merge branch 'pci/controller/imx6'

Merge branch 'pci/controller/imx6'

- Fix a code restructuring error that caused i.MX8MM and i.MX8MP Endpoints
  to fail to establish link (Richard Zhu)

- Fix i.MX8MP Endpoint occasional failure to trigger MSI by enforcing
  outbound alignment requirement (Richard Zhu)

- Call phy_power_off() in the .probe() error path (Frank Li)

- Rename internal names from imx6_* to imx_* since i.MX7/8/9 are also
  supported (Frank Li)

- Manage Refclk by using SoC-specific callbacks instead of switch
  statements (Frank Li)

- Manage core reset by using SoC-specific callbacks instead of switch
  statements (Frank Li)

- Expand comments for erratum ERR010728 workaround (Frank Li)

- Use generic PHY APIs to configure mode, speed, and submode, which is
  harmless for devices that implement their own internal PHY management and
  don't set the generic imx_pcie->phy (Frank Li)

- Add i.MX8Q (i.MX8QM, i.MX8QXP, and i.MX8DXL) DT binding and driver Root
  Complex support (Richard Zhu)

* pci/controller/imx6:
  PCI: imx6: Add i.MX8Q PCIe Root Complex (RC) support
  PCI: imx6: Call common PHY API to set mode, speed, and submode
  dt-bindings: PCI: imx6q-pcie: Add i.MX8Q PCIe compatible string
  PCI: imx6: Consolidate redundant if-checks
  PCI: imx6: Improve comment for workaround ERR010728
  PCI: imx6: Simplify switch-case logic by involve core_reset callback
  PCI: imx6: Introduce SoC specific callbacks for controlling REFCLK
  PCI: imx6: Rename imx6_* with imx_*
  PCI: imx6: Fix missing call to phy_power_off() in error handling
  PCI: imx6: Fix i.MX8MP PCIe EP's occasional failure to trigger MSI
  PCI: imx6: Fix establish link failure in EP mode for i.MX8MM and i.MX8MP