Fix warning at drivers/pci/msi/msi.h:121.

Recently, I added a PCI to PCIe bridge adaptor and a PCIe NVME card
to my rp3440. Then, I noticed this warning at boot:

 WARNING: CPU: 0 PID: 10 at drivers/pci/msi/msi.h:121 pci_msi_setup_msi_irqs+0x68/0x90
 CPU: 0 PID: 10 Comm: kworker/u32:0 Not tainted 6.9.7-parisc64 #1  Debian 6.9.7-1
 Hardware name: 9000/800/rp3440
 Workqueue: async async_run_entry_fn

We need to select PCI_MSI_ARCH_FALLBACKS when PCI_MSI is selected.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org	# v6.0+
Signed-off-by: Helge Deller <deller@gmx.de>