powerpc/pcidn: Make IOV setup routines static

These are only used locally. It fixes these W=1 compile errors :

../arch/powerpc/platforms/pseries/pci.c:58:5: error: no previous prototype for ‘pseries_send_map_pe’ [-Werror=missing-prototypes]
   58 | int pseries_send_map_pe(struct pci_dev *pdev,
      |     ^~~~~~~~~~~~~~~~~~~
../arch/powerpc/platforms/pseries/pci.c:91:6: error: no previous prototype for ‘pseries_set_pe_num’ [-Werror=missing-prototypes]
   91 | void pseries_set_pe_num(struct pci_dev *pdev, u16 vf_index, __be16 pe_num)
      |      ^~~~~~~~~~~~~~~~~~
../arch/powerpc/platforms/pseries/pci.c:105:5: error: no previous prototype for ‘pseries_associate_pes’ [-Werror=missing-prototypes]
  105 | int pseries_associate_pes(struct pci_dev *pdev, u16 num_vfs)
      |     ^~~~~~~~~~~~~~~~~~~~~
../arch/powerpc/platforms/pseries/pci.c:149:5: error: no previous prototype for ‘pseries_pci_sriov_enable’ [-Werror=missing-prototypes]
  149 | int pseries_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~
../arch/powerpc/platforms/pseries/pci.c:192:5: error: no previous prototype for ‘pseries_pcibios_sriov_enable’ [-Werror=missing-prototypes]
  192 | int pseries_pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../arch/powerpc/platforms/pseries/pci.c:199:5: error: no previous prototype for ‘pseries_pcibios_sriov_disable’ [-Werror=missing-prototypes]
  199 | int pseries_pcibios_sriov_disable(struct pci_dev *pdev)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210104143206.695198-23-clg@kaod.org