drm/amd/virt: For SRIOV send GPU reset directly to TDR queue.

No need to to trigger another work queue inside the work queue.

v3:

Problem:
Extra reset caused by host side FLR notification
following guest side triggered reset.
Fix: Preven qeuing flr_work from mailbox irq if guest
already executing a reset.

Suggested-by: Liu Shaoyun <Shaoyun.Liu@amd.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Liu Shaoyun <Shaoyun.Liu@amd.com>
Link: https://www.spinics.net/lists/amd-gfx/msg74114.html