[efi] Generalise snpnet_pci_info() to efi_locate_device()

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/efi/efi_utils.h

@@ -13,6 +13,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 extern EFI_DEVICE_PATH_PROTOCOL *
 efi_devpath_end ( EFI_DEVICE_PATH_PROTOCOL *path );
+extern int efi_locate_device ( EFI_HANDLE device, EFI_GUID *protocol,
+			       EFI_HANDLE *parent );
 extern int efi_child_add ( EFI_HANDLE parent, EFI_HANDLE child );
 extern void efi_child_del ( EFI_HANDLE parent, EFI_HANDLE child );