Revert "PCI/MSI: Provide stubs for IMS functions"

[ Upstream commit 372c6692 ]

This reverts commit 41efa431.

IMS (Interrupt Message Store) support appeared in v6.2, but there are no
users yet.

Remove it for now.  We can add it back when a user comes along.  If this is
re-added later, this could be squashed with these commits:

  0194425a ("PCI/MSI: Provide IMS (Interrupt Message Store) support")
  c9e5bea2 ("PCI/MSI: Provide pci_ims_alloc/free_irq()")

which added the non-stub implementations.

Link: https://lore.kernel.org/r/20240410221307.2162676-2-helgaas@kernel.org


Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>