Generalize -machine command line option

-machine somehow suggests that it selects the machine, but it doesn't.
Fix that before this command is set in stone.

Actually, -machine should supersede -M and allow to introduce arbitrary
per-machine options to the command line. That will change the internal
realization again, but we will be able to keep the user interface
stable.

Tested-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qemu-config.c b/qemu-config.c
index 93d20c6..b2ec40b 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -464,9 +464,14 @@
 
 static QemuOptsList qemu_machine_opts = {
     .name = "machine",
+    .implied_opt_name = "type",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_machine_opts.head),
     .desc = {
         {
+            .name = "type",
+            .type = QEMU_OPT_STRING,
+            .help = "emulated machine"
+        }, {
             .name = "accel",
             .type = QEMU_OPT_STRING,
             .help = "accelerator list",