PCI: j721e: Add TI J784S4 PCIe configuration

Add PCIe configuration for J784S4 SoC platform which has 4x lane
support.

Link: https://lore.kernel.org/linux-pci/20231128054402.2155183-6-s-vadapalli@ti.com


Tested-by: Achal Verma <a-verma1@ti.com>
Signed-off-by: Matt Ranostay <mranostay@ti.com>
Signed-off-by: Achal Verma <a-verma1@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Roger Quadros <rogerq@kernel.org>