Drop tegra specific label from policy.

This label was originally used for Motorola
Xoom devices. nvmap is the tegra gpu memory
manager and the various nvhost drivers are
for tegra graphics related functionality,
i.e. display serial interface, image signal
processor, or media processing stuff.

Only grouper and tilapia presently need this
policy.

Change-Id: I2a7000f69abf3185724d88d428e8237e0ca436ec