gpu: nvgpu: Add subctx programming for MIG

This CL covers the following code changes,
1) Added api to init inst_block for more than one subctxs.
2) Added logic to limit the subctx bind based on
   max. VEID count allocated to a gr instance.
3) Renamed nvgpu_grmgr_get_gr_runlist_id.

JIRA NVGPU-5647

Change-Id: Ifec8164a9e5f46fbd0538c3dd50e19ee63667a54
Signed-off-by: Lakshmanan M <lm@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2418463
Reviewed-by: automaticguardword <automaticguardword@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Rajesh Devaraj <rdevaraj@nvidia.com>
Reviewed-by: Dinesh T <dt@nvidia.com>
Reviewed-by: Vaibhav Kachore <vkachore@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit

libs/dgpu/libnvgpu-drv-dgpu_safe.export

@@ -402,6 +402,7 @@ nvgpu_free_fixed
 nvgpu_free_gr_ctx_struct
 nvgpu_get
 nvgpu_get_gpfifo_entry_size
+nvgpu_channel_get_max_subctx_count
 nvgpu_get_pte
 nvgpu_gmmu_default_big_page_size
 nvgpu_gmmu_init_page_table

libs/igpu/libnvgpu-drv-igpu_safe.export

@@ -416,6 +416,7 @@ nvgpu_free_fixed
 nvgpu_free_gr_ctx_struct
 nvgpu_get
 nvgpu_get_gpfifo_entry_size
+nvgpu_channel_get_max_subctx_count
 nvgpu_get_pte
 nvgpu_gmmu_default_big_page_size
 nvgpu_gmmu_init_page_table