Make it easier to add compat properties, by
adding macros for properties duplicated across
machine types.

Note: there could be bugs in compat properties,
this patch does not attempt to address them,
the code is bug for bug identical to the original.

Tested by: generated a preprocessed file, sorted and
compared to sorted original.
Lightly tested on x86_64.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>