All platform MSI users and the PCI/MSI code handle per device MSI domains
when the irqdomain associated to the device provides MSI parent
functionality.

Remove the "global" PCI/MSI and platform domain related code and provide
the MSI parent functionality by filling in msi_parent_ops.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Shivamurthy Shastri <shivamurthy.shastri@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240623142235.514419280@linutronix.de