powerpc/pseries/eeh: Make pseries_send_allow_unfreeze() static

Only used locally. It fixes this W=1 compile error :

../arch/powerpc/platforms/pseries/eeh_pseries.c:697:5: error: no previous prototype for ‘pseries_send_allow_unfreeze’ [-Werror=missing-prototypes]
  697 | int pseries_send_allow_unfreeze(struct pci_dn *pdn,
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210104143206.695198-24-clg@kaod.org

arch/powerpc/platforms/pseries/eeh_pseries.c

@@ -694,8 +694,7 @@ static int pseries_eeh_write_config(struct eeh_dev *edev, int where, int size, u
 }
 
 #ifdef CONFIG_PCI_IOV
-int pseries_send_allow_unfreeze(struct pci_dn *pdn,
-				u16 *vf_pe_array, int cur_vfs)
+static int pseries_send_allow_unfreeze(struct pci_dn *pdn, u16 *vf_pe_array, int cur_vfs)
 {
 	int rc;
 	int ibm_allow_unfreeze = rtas_token("ibm,open-sriov-allow-unfreeze");