oem-ibm: remove OSStart as indication host is running

This logic is checking whether PHYP is at standby or runtime. The
OSStart was never implemented by PHYP so it should not be looked at to
determine this state. The hostboot team is going to utilize this
BootProgress to indicate when they are starting PHYP.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: Iebb1260232c60ae77a0f0e25e79fd2fa354238ba