drm/amdgpu/sriov: Need to set in_gpu_reset flag to back after gpu reset

After host os reset gpu reset, need to set flag in_gpu_reset to
zero.

Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>