Since d36f165d952 (qdev: make properties array "const"), we can
define our Property structure const. Do this across the entire tree.
There are a few other minor changes:
- Two instances where it was obvious that an empty property list
could be removed entirely. There are other empty lists that
probably should be removed, but I didn't look further into usage.
- In hw/misc/xlnx-versal-trng.c, adjust a Property to use the
correct PropertyInfo in the definition, rather than setting
it at runtime.
- One instance where { } was used instead of DEFINE_PROP_END_OF_LIST.
Not a bug, but wrong style.