sched/debug: Make sysrq prints of sched debug data optional

Calls to sysrq_sched_debug_show() can yield rather verbose output
which contributes to log spew and, under heavy load, may increase
the chances of a watchdog bark.

Make printing of this data optional with the introduction of a
new Kconfig, CONFIG_SYSRQ_SCHED_DEBUG.

Change-Id: I5f54d901d0dea403109f7ac33b8881d967a899ed
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 2f9ac8f..20e311b 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -382,10 +382,12 @@
 	return 0;
 }
 
+#ifdef CONFIG_SYSRQ_SCHED_DEBUG
 void sysrq_sched_debug_show(void)
 {
 	sched_debug_show(NULL, NULL);
 }
+#endif
 
 static int sched_debug_open(struct inode *inode, struct file *filp)
 {