s390/pci: inform when missing required facilities

when we're missing the necessary machine facilities zPCI can
not function. Until now it would silently fail to be initialized,
add an informational print.
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/pci/pci.c

@@ -851,8 +851,10 @@ static int __init pci_base_init(void)
 	if (!s390_pci_probe)
 		return 0;
 
-	if (!test_facility(69) || !test_facility(71))
+	if (!test_facility(69) || !test_facility(71)) {
+		pr_info("PCI is not supported because CPU facilities 69 or 71 are not available\n");
 		return 0;
+	}
 
 	if (test_facility(153) && !s390_pci_no_mio) {
 		static_branch_enable(&have_mio);