gpu: nvgpu: FIFO SWUD

- Add template for FIFO SWUD (SW Unit Design Document).
- Add doxygen documentation in top.h, fifo.h and engines.h
- Removed
 -- nvgpu_pbdma_exception_info
 -- nvgpu_engine_exception_info

JIRA NVGPU-3589

Change-Id: Ie4e80e75bc13d6cefe1835e5f176f313456f2351
Signed-off-by: Seema Khowala <seemaj@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2134671
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-misra <svc-mobile-misra@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Thomas Fleury <tfleury@nvidia.com>
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/common/fifo/engines.c

@@ -461,7 +461,7 @@ int nvgpu_engine_wait_for_idle(struct gk20a *g)
 	return ret;
 }
 
-#endif /* NVGPU_ENGINE */
+#endif /* CONFIG_NVGPU_FIFO_ENGINE_ACTIVITY */
 
 int nvgpu_engine_setup_sw(struct gk20a *g)
 {