powerpc/chrp/pci: Make some functions static

These functions can all be static, make it so. Fix warnings treated as
errors with W=1:

  arch/powerpc/platforms/chrp/pci.c:34:5: error: no previous prototype for ‘gg2_read_config’ [-Werror=missing-prototypes]
  arch/powerpc/platforms/chrp/pci.c:61:5: error: no previous prototype for ‘gg2_write_config’ [-Werror=missing-prototypes]
  arch/powerpc/platforms/chrp/pci.c:97:5: error: no previous prototype for ‘rtas_read_config’ [-Werror=missing-prototypes]
  arch/powerpc/platforms/chrp/pci.c:112:5: error: no previous prototype for ‘rtas_write_config’ [-Werror=missing-prototypes]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/chrp/pci.c

@@ -31,7 +31,7 @@ void __iomem *gg2_pci_config_base;
  * limit the bus number to 3 bits
  */
 
-int gg2_read_config(struct pci_bus *bus, unsigned int devfn, int off,
+static int gg2_read_config(struct pci_bus *bus, unsigned int devfn, int off,
 			   int len, u32 *val)
 {
 	volatile void __iomem *cfg_data;
@@ -58,7 +58,7 @@ int gg2_read_config(struct pci_bus *bus, unsigned int devfn, int off,
 	return PCIBIOS_SUCCESSFUL;
 }
 
-int gg2_write_config(struct pci_bus *bus, unsigned int devfn, int off,
+static int gg2_write_config(struct pci_bus *bus, unsigned int devfn, int off,
 			    int len, u32 val)
 {
 	volatile void __iomem *cfg_data;
@@ -94,8 +94,8 @@ static struct pci_ops gg2_pci_ops =
 /*
  * Access functions for PCI config space using RTAS calls.
  */
-int rtas_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
-		     int len, u32 *val)
+static int rtas_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
+			    int len, u32 *val)
 {
 	struct pci_controller *hose = pci_bus_to_host(bus);
 	unsigned long addr = (offset & 0xff) | ((devfn & 0xff) << 8)
@@ -109,8 +109,8 @@ int rtas_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
 	return rval? PCIBIOS_DEVICE_NOT_FOUND: PCIBIOS_SUCCESSFUL;
 }
 
-int rtas_write_config(struct pci_bus *bus, unsigned int devfn, int offset,
-		      int len, u32 val)
+static int rtas_write_config(struct pci_bus *bus, unsigned int devfn, int offset,
+			     int len, u32 val)
 {
 	struct pci_controller *hose = pci_bus_to_host(bus);
 	unsigned long addr = (offset & 0xff) | ((devfn & 0xff) << 8)