PCI/MSI: Rename "struct msi_chip" to "struct msi_controller"

"msi_chip" isn't very descriptive, so rename it to "msi_controller".  That
tells a little more about what it does and is already used in device tree
bindings.

No functional change.

[bhelgaas: changelog, change *only* the struct name so it's reviewable]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/host/pci-keystone.h b/drivers/pci/host/pci-keystone.h
index 1fc1fce..478d932 100644
--- a/drivers/pci/host/pci-keystone.h
+++ b/drivers/pci/host/pci-keystone.h
@@ -55,4 +55,4 @@
 void ks_dw_pcie_msi_clear_irq(struct pcie_port *pp, int irq);
 void ks_dw_pcie_v3_65_scan_bus(struct pcie_port *pp);
 int ks_dw_pcie_msi_host_init(struct pcie_port *pp,
-		struct msi_chip *chip);
+		struct msi_controller *chip);