lscpu: improve vmware detection

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

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