gpu: nvgpu: suppress unbind operation

Unbind on nvgpu results in kernel panic.
Suppress it to avoid kernel panic.
Proper fix should follow later on.

bug 1779085

Change-Id: Ibc966ac031f7f04406db63310e2f5ea126649ac0
Signed-off-by: Sri Krishna chowdary <schowdary@nvidia.com>
Reviewed-on: http://git-master/r/1212759
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

drivers/gpu/nvgpu/gk20a/gk20a.c

@@ -1764,6 +1764,7 @@ static struct platform_driver gk20a_driver = {
 #ifdef CONFIG_PM
 		.pm = &gk20a_pm_ops,
 #endif
+		.suppress_bind_attrs = true,
 	}
 };