amdgpu: fix asic initialization for virtualized environments (v2)

When executing in a PCI passthrough based virtuzliation environemnt, the
hypervisor will usually attempt to send a PCIe bus reset signal to the
ASIC when the VM reboots. In this scenario, the card is not correctly
initialized, but we still consider it to be posted. Therefore, in a
passthrough based environemnt we should always post the card to guarantee
it is in a good state for driver initialization.

However, if we are operating in SR-IOV mode it is up to the GIM driver
to manage the asic state, therefore we should not post the card (and
shouldn't be able to do it either).

v2: add missing semi-colon

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Andres Rodriguez <andres.rodriguez@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>