stackprotector: add boot_init_stack_canary()

add the boot_init_stack_canary() and make the secondary idle threads
use it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/linux/stackprotector.h b/include/linux/stackprotector.h
index d3e8bbe..422e71a 100644
--- a/include/linux/stackprotector.h
+++ b/include/linux/stackprotector.h
@@ -3,6 +3,10 @@
 
 #ifdef CONFIG_CC_STACKPROTECTOR
 # include <asm/stackprotector.h>
+#else
+static inline void boot_init_stack_canary(void)
+{
+}
 #endif
 
 #endif