MAINTAINERS: Update John Stultz's email

Update my email address.

Signed-off-by: John Stultz <john.stultz@linaro.org>

MAINTAINERS

diff --git a/MAINTAINERS b/MAINTAINERS
index 59203e7..b908912 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6282,7 +6282,7 @@
 F:	drivers/dma/dw_dmac.c
 
 TIMEKEEPING, NTP
-M:	John Stultz <johnstul@us.ibm.com>
+M:	John Stultz <john.stultz@linaro.org>
 M:	Thomas Gleixner <tglx@linutronix.de>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core
 S:	Supported