drm/amdgpu: fix documentation errors in gmc v12.0

Fix up parameter descriptions.
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c

@@ -282,6 +282,8 @@ static void gmc_v12_0_flush_vm_hub(struct amdgpu_device *adev, uint32_t vmid,
  *
  * @adev: amdgpu_device pointer
  * @vmid: vm instance to flush
+ * @vmhub: which hub to flush
+ * @flush_type: the flush type
  *
  * Flush the TLB for the requested page table.
  */
@@ -321,6 +323,9 @@ static void gmc_v12_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
  *
  * @adev: amdgpu_device pointer
  * @pasid: pasid to be flush
+ * @flush_type: the flush type
+ * @all_hub: flush all hubs
+ * @inst: is used to select which instance of KIQ to use for the invalidation
  *
  * Flush the TLB for the requested pasid.
  */