x86: log XPTI enabled status

x86: log XPTI enabled status

At the same time also report the state of the two defined
ARCH_CAPABILITIES MSR bits. To avoid further complicating the
conditional around that printk(), drop it (it's a debug level one only
anyway).

Issue the main message without any XENLOG_*, and also drop XENLOG_INFO
from the respective BTI message, to make sure they're visible at default
log level also in release builds.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>