gpu: nvgpu: bvec for struct nvgpu_tsg_sm_error_state fields

Add Setter and Getter methods for accessing tsg->sm_error_states.
Getter returns a constant pointer for struct nvgpu_tsg_sm_error_state.
This renders it unnecessary to add BVEC for above fields for the struct
in multiple locations. The current design ensures that only a constant
pointer is obtained from the owner unit i.e. FIFO.

The following new methods are added. Both unit tests and BVEC tests
are added for them as well.

nvgpu_tsg_store_sm_error_state
nvgpu_tsg_get_sm_error_state

Jira NVGPU-6947

Change-Id: I82c22a2774862c8579baa41b6fb8292fa164704a
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
(cherry picked from commit 79574638671a0c6efe41cd3423668fcd1bd96826)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2556938
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: svc_kernel_abi <svc_kernel_abi@nvidia.com>
Reviewed-by: Shashank Singh <shashsingh@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Vaibhav Kachore <vkachore@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit

libs/igpu/libnvgpu-drv-igpu_safe.export

@@ -700,6 +700,8 @@ nvgpu_timeout_expired_fault_injection
 nvgpu_timeout_init
 nvgpu_timeout_peek_expired
 nvgpu_timers_get_fault_injection
+nvgpu_tsg_store_sm_error_state
+nvgpu_tsg_get_sm_error_state
 nvgpu_tsg_abort
 nvgpu_tsg_bind_channel
 nvgpu_tsg_check_and_get_from_id