MAINTAINERS: update ath6kl git location

The git tree is in github.com nowadays.
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

MAINTAINERS

@@ -1406,7 +1406,7 @@ ATHEROS ATH6KL WIRELESS DRIVER
 M:	Kalle Valo <kvalo@qca.qualcomm.com>
 L:	linux-wireless@vger.kernel.org
 W:	http://wireless.kernel.org/en/users/Drivers/ath6kl
-T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath6kl.git
+T:	git git://github.com/kvalo/ath.git
 S:	Supported
 F:	drivers/net/wireless/ath/ath6kl/