nyan: Add /dev/nvhost-tsec to group "video"

L4T stuff opens /dev/nvhost-tsec.  Set permissions to read/writable by group
"video".

BUG=chrome-os-partner:28268
TEST=Built ChromeOS for nyan with new rules file, and made sure
/dev/nvhost-tsec has the proper permissions.

Signed-off-by: Andrew Chew <achew@nvidia.com>

Change-Id: Ic2f13c41fc1c0b9dfae946d005494cf19b8d0c6e
Reviewed-on: https://chromium-review.googlesource.com/199277
Tested-by: Andrew Chew <achew@nvidia.com>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Andrew Chew <achew@nvidia.com>
diff --git a/overlay-nyan/sys-apps/nvrm/files/51-nvrm.rules b/overlay-nyan/sys-apps/nvrm/files/51-nvrm.rules
index b4a28da..6ae5aab 100644
--- a/overlay-nyan/sys-apps/nvrm/files/51-nvrm.rules
+++ b/overlay-nyan/sys-apps/nvrm/files/51-nvrm.rules
@@ -5,6 +5,7 @@
 KERNEL=="nvhost-ctrl-gpu", GROUP="video"
 KERNEL=="nvhost-gpu", GROUP="video"
 KERNEL=="nvhost-msenc", GROUP="video"
+KERNEL=="nvhost-tsec", GROUP="video"
 KERNEL=="nvhost-vic", GROUP="video"
 KERNEL=="nvmap", GROUP="video"
 KERNEL=="tegra_dc_0", GROUP="video"