MAINTAINERS: Update tegra maintainer information

A couple of changes to the Tegra maintainership setup:

I'm very glad to bring on Stephen Warren on board as a maintainer. The
work he has done so far is excellent, and the fact that he works for
Nvidia means he has long-term interest in the platform.

Erik Gilling did an astounding amount of work on getting things up and
running but has been a silent partner on the maintainership side for a
while, and is stepping down. Thanks for your contributions so far, Erik.

Finally, update the git URL since I'll take over running the main repo
for a while.

Overall maintainership model isn't changing much at this time: We'll all
three review patches as appropriate, and one of us will collect the main
repo (me at this time).

Signed-off-by: Olof Johansson <[e-mail]>
Cc: Erik Gilling <[e-mail]>
Acked-by: Colin Cross <[e-mail]>
Acked-by: Stephen Warren <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

MAINTAINERS

···
 
 TEGRA SUPPORT
 M:	Colin Cross <[e-mail]>
-M:	Erik Gilling <[e-mail]>
 M:	Olof Johansson <[e-mail]>
+M:	Stephen Warren <[e-mail]>
 L:	[e-mail]
-T:	git git://android.git.kernel.org/kernel/tegra.git
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/olof/tegra.git
 S:	Supported
 F:	arch/arm/mach-tegra