pc: cleanup 1.4 compat support

Make 1.4 compat code call the 1.6 one, reducing
code duplication. Add comment explaining why we can't
make 1.4 call 1.5 as usual.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>

hw/i386/pc_piix.c

@@ -265,8 +265,8 @@ static void pc_init_pci_1_4(QEMUMachineInitArgs *args)
 {
     x86_cpu_compat_set_features("n270", FEAT_1_ECX, 0, CPUID_EXT_MOVBE);
     x86_cpu_compat_set_features("Westmere", FEAT_1_ECX, 0, CPUID_EXT_PCLMULQDQ);
-    has_pci_info = false;
-    pc_init_pci(args);
+    /* 1.5 was special - it enabled pvpanic in builtin machine */
+    pc_init_pci_1_6(args);
 }
 
 static void pc_init_pci_1_3(QEMUMachineInitArgs *args)

hw/i386/pc_q35.c

@@ -234,8 +234,8 @@ static void pc_q35_init_1_4(QEMUMachineInitArgs *args)
 {
     x86_cpu_compat_set_features("n270", FEAT_1_ECX, 0, CPUID_EXT_MOVBE);
     x86_cpu_compat_set_features("Westmere", FEAT_1_ECX, 0, CPUID_EXT_PCLMULQDQ);
-    has_pci_info = false;
-    pc_q35_init(args);
+    /* 1.5 was special - it enabled pvpanic in builtin machine */
+    pc_q35_init_1_6(args);
 }
 
 static QEMUMachine pc_q35_machine_v1_6 = {