paravirt: noreplace-paravirt is implemented for x86 and ia-64

kernel-parameters.txt lists 'noreplace-paravirt' parameter as being
limited to X86-32, which is incorrect -- it's actually supported by
x86-32, x86-64 and ia-64.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>