don't use PHNE_35793 on HPVM

from http://www12.itrc.hp.com/service/patch/patchDetail.do?patchid=PHNE_35793&sel={hpux:11.23,}&BC=main|search|

       - An HPVM guest that uses a virtual interface that belongs
         to an IGELAN interface configured on the HPVM host can
         experience hangs with network services like ping, NFS,
         rcp, ftp for data transfers which use full-sized
         frames.  This behavior is observed with HPVM 2.0 and
         HPVM 3.0.

oh, and HPVM 1.2 either