[MIPS] pnx8550: Fix write_config_byte() PCI config space accessor

There's a serious typo in the function:
  arch/mips/pci/ops-pnx8550.c:write_config_byte()

The parameter passed to the function config_access() is PCI_CMD_CONFIG_READ
instead of PCI_CMD_CONFIG_WRITE. This renders any attempts to write
a single byte to the PCI configuration registers useless.

This problem does not exist for write_config_word() nor write_config_dword().

This problem has been there since kernel v2.6.17 and is still there
as of kernel v2.6.19.1.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/pci/ops-pnx8550.c

@@ -202,7 +202,7 @@ write_config_byte(struct pci_bus *bus, unsigned int devfn, int where, u8 val)
 		break;
 	}
 
-	err = config_access(PCI_CMD_CONFIG_READ, bus, devfn, where, ~(1 << (where & 3)), &data);
+	err = config_access(PCI_CMD_CONFIG_WRITE, bus, devfn, where, ~(1 << (where & 3)), &data);
 
 	return err;
 }