PCI: qcom: Wait PCIE_RESET_CONFIG_WAIT_MS after link-up IRQ

PCI: qcom: Wait PCIE_RESET_CONFIG_WAIT_MS after link-up IRQ

Per PCIe r6.0, sec 6.6.1, software must generally wait a minimum of
100ms (PCIE_RESET_CONFIG_WAIT_MS) after Link training completes before
sending a Configuration Request.

Prior to 36971d6c5a9a ("PCI: qcom: Don't wait for link if we can detect
Link Up"), qcom used dw_pcie_wait_for_link(), which waited between 0
and 90ms after the link came up before we enumerate the bus, and this
was apparently enough for most devices.

After 36971d6c5a9a, qcom_pcie_global_irq_thread() started enumeration
immediately when handling the link-up IRQ, and devices (e.g., Laszlo
Fiat's PLEXTOR PX-256M8PeGN NVMe SSD) may not be ready to handle config
requests yet.

Delay PCIE_RESET_CONFIG_WAIT_MS after the link-up IRQ before starting
enumeration.

Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Link: https://patch.msgid.link/20250625102347.1205584-13-cassel@kernel.org