lscpu: detect OS/400 and pHyp hypervisors

lscpu: detect OS/400 and pHyp hypervisors

This patch comes originally from openSUSE / SLE. Author was probably
Petr Uzel.
Internal SUSE references: fate310255, sr226509

In comparison to the original patch we have slightly corrected iSeries
and pSeries detection according to Alexander Graf's comments on
util-linux@vger.kernel.org. Maybe we would need to add some more code
to detect pSeries emulated by Qemu/KVM.

CC: Stanislav Brabec <sbrabec@suse.cz>
CC: Petr Uzel <petr.uzel@suse.cz>
CC: Alexander Graf <agraf@suse.de>
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>