x86/shadow: adjust and move sh_type_to_size[]

x86/shadow: adjust and move sh_type_to_size[]

Drop the SH_type_none entry - there are no allocation attempts with
this type, and there also shouldn't be any. Adjust the shadow_size()
alternative path to match that change. Also generalize two related
assertions.

While there move the entire table and the respective part of the comment
there to hvm.c, resulting in one less #ifdef. In the course of the
movement switch to using designated initializers.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>