PCI: dwc: Fix missing iATU setup when ECAM is enabled

PCI: dwc: Fix missing iATU setup when ECAM is enabled

When ECAM is enabled, the driver skipped calling dw_pcie_iatu_setup()
before configuring ECAM iATU entries. This left IO and MEM outbound
windows unprogrammed, resulting in broken IO transactions. Additionally,
dw_pcie_config_ecam_iatu() was only called during host initialization,
so ECAM-related iATU entries were not restored after suspend/resume,
leading to failures in configuration space access

To resolve these issues, move the ECAM iATU configuration to
dw_pcie_iatu_setup(), and invoke dw_pcie_iatu_setup() when ECAM is
enabled.

Furthermore, add error checks in dw_pcie_prog_outbound_atu() and
dw_pcie_prog_inbound_atu() such that an error is returned if the caller is
trying to program an iATU that is outside the number of iATUs supported by
the controller.

Fixes: f6fd357f7afb ("PCI: dwc: Prepare the driver for enabling ECAM mechanism using iATU 'CFG Shift Feature'")
Reported-by: Maciej W. Rozycki <macro@orcam.me.uk>
Closes: https://lore.kernel.org/all/alpine.DEB.2.21.2511280256260.36486@angie.orcam.me.uk/
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Co-developed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
[mani: used imperative tone]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Tested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hans Zhang <zhanghuabing@ecosda.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable+noautosel@kernel.org # depends on Clean up iATU index usage in dw_pcie_iatu_setup()
Link: https://patch.msgid.link/20260127151038.1484881-8-cassel@kernel.org