MAINTAIERS/printk: Add link to printk git

It might also help to avoid confusion with the historic
pmladek/printk.git that has got obsoleted by printk/linux.git
in February 2020.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220105094157.26216-3-pmladek@suse.com

Author: pmladek

MAINTAINERS

@@ -15329,6 +15329,7 @@ M:	Sergey Senozhatsky <senozhatsky@chromium.org>
 R:	Steven Rostedt <rostedt@goodmis.org>
 R:	John Ogness <john.ogness@linutronix.de>
 S:	Maintained
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux.git
 F:	include/linux/printk.h
 F:	kernel/printk/