PCI: dwc: Add Sophgo SG2044 PCIe controller driver in Root Complex mode

Add driver support for DesignWare based PCIe controller in SG2044 SoC. The
driver currently supports the Root Complex mode.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
[mani: renamed the driver to 'pcie-sophgo.c' and Kconfig fix]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: whitespace]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250504004420.202685-3-inochiama@gmail.com