hw/ppc/spapr,e500: Use new property "stdout-path" for boot console

Linux kernel commit 2a9d832cc9aae21ea827520fef635b6c49a06c6d
(of: Add bindings for chosen node, stdout-path) deprecated chosen property
"linux,stdout-path" and "stdout".

Introduce the new property "stdout-path" and continue supporting the older
property to remain compatible with existing/older firmware. This older property
can be deprecated after 5 years.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/e500.c

@@ -120,7 +120,14 @@ static void dt_serial_create(void *fdt, unsigned long long offset,
     qemu_fdt_setprop_string(fdt, "/aliases", alias, ser);
 
     if (defcon) {
+        /*
+         * "linux,stdout-path" and "stdout" properties are deprecated by linux
+         * kernel. New platforms should only use the "stdout-path" property. Set
+         * the new property and continue using older property to remain
+         * compatible with the existing firmware.
+         */
         qemu_fdt_setprop_string(fdt, "/chosen", "linux,stdout-path", ser);
+        qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", ser);
     }
 }
 

hw/ppc/spapr.c

@@ -1053,7 +1053,14 @@ static void spapr_dt_chosen(sPAPRMachineState *spapr, void *fdt)
     }
 
     if (!spapr->has_graphics && stdout_path) {
+        /*
+         * "linux,stdout-path" and "stdout" properties are deprecated by linux
+         * kernel. New platforms should only use the "stdout-path" property. Set
+         * the new property and continue using older property to remain
+         * compatible with the existing firmware.
+         */
         _FDT(fdt_setprop_string(fdt, chosen, "linux,stdout-path", stdout_path));
+        _FDT(fdt_setprop_string(fdt, chosen, "stdout-path", stdout_path));
     }
 
     spapr_dt_ov5_platform_support(fdt, chosen);