x86: don't use BAD_APICID for non-APICID fields

x86: don't use BAD_APICID for non-APICID fields

BAD_APICID is used by cpuinfo_x86's phys_proc_id, cpu_core_id
and compute_unit_id even though these fields don't hold an APIC ID
itself but rather its derivative.

Provide appropriate macros for each of those three (and make them
unsigned).

This also fixes regression introduced by commit 2090f14c5cbd ("sysctl:
make XEN_SYSCTL_topologyinfo sysctl a little more efficient") which
leaked BAD_APICID into common code, breaking ARM.

Reported-by: Julien Grall <julien.grall@linaro.org>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Ditch INVALID_{CORE,SOCKET}ID in favor of always using
XEN_INVALID_{CORE,SOCKET}_ID.

Signed-off-by: Jan Beulich <jbeulich@suse.com>