PCI: iproc: Implement MSI controller node detection with of_msi_xlate()

PCI: iproc: Implement MSI controller node detection with of_msi_xlate()

The functionality implemented in the iproc driver in order to detect an
OF MSI controller node is now fully implemented in of_msi_xlate().

Replace the current msi-map/msi-parent parsing code with of_msi_xlate().

Since of_msi_xlate() is also a deviceID mapping API, pass in a fictitious
0 as deviceID - the driver only requires detecting the OF MSI controller
node not the deviceID mapping per-se (of_msi_xlate() return value is
ignored for the same reason).

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20251021124103.198419-5-lpieralisi@kernel.org