PCI: Remove unused HAVE_PCI_SET_MWI

Remove unused HAVE_PCI_SET_MWI.

Link: https://lore.kernel.org/r/03f20cac-708d-7897-c7c7-cb4e63cfd991@gmail.comSigned-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

include/linux/pci.h

@@ -1190,7 +1190,6 @@ void pci_clear_master(struct pci_dev *dev);
 
 int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state);
 int pci_set_cacheline_size(struct pci_dev *dev);
-#define HAVE_PCI_SET_MWI
 int __must_check pci_set_mwi(struct pci_dev *dev);
 int __must_check pcim_set_mwi(struct pci_dev *dev);
 int pci_try_set_mwi(struct pci_dev *dev);