MAINTAINERS: Remove Terje Bergström as Tegra DRM maintainer

Terje doesn't work on host1x anymore and doesn't have the time to help
maintain the host1x and related drivers.
Acked-by: NTerje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>

MAINTAINERS

@@ -3842,7 +3842,6 @@ F:	include/drm/gma500*
 
 DRM DRIVERS FOR NVIDIA TEGRA
 M:	Thierry Reding <thierry.reding@gmail.com>
-M:	Terje Bergström <tbergstrom@nvidia.com>
 L:	dri-devel@lists.freedesktop.org
 L:	linux-tegra@vger.kernel.org
 T:	git git://anongit.freedesktop.org/tegra/linux.git