NetKVM: BZ#978296 Incorrect link state indications in PM_PowerStateTransition

OID_GEN_MEDIA_CONNECT_STATUS dropped because it is
not required on NDIS6
NetKVM: BZ#978296 Incorrect link state indications in PM_PowerStateTransition

  1. Duplicate link state indications dropped
  2. Link state indication logic refactored for simplicity
[vioscsi] add msi support
serial: remove code which handled write requests resubmission.

The code was removed from two reasons:

1. It caused a duplicated write if qemu notify us without
   returning the previous descriptor.

2. It is no longer needed as the current implemention
   doesn't allow the virt queue to fill up.