Add debugger entry points for SCORE

This patch series adds an export which can be set by system debuggers to direct the hard lockup and soft lockup detector to trigger a breakpoint exception and enter a debugger if one is active. It is assumed that if someone sets this variable, then an breakpoint handler of some sort will be actively loaded or registered via the notify die handler chain.

This addition is extremely useful for debugging hard and soft lockups real time and quickly from a console debugger.

---
 arch/score/include/asm/kdebug.h | 4 ++++
 1 file changed, 4 insertions(+)

index a666e51..9d3747a 100644
@@ -3,4 +3,8 @@
 
 #include <asm-generic/kdebug.h>
 
+static inline void arch_breakpoint(void)
+{
+}
+
 #endif /* _ASM_SCORE_KDEBUG_H */

1.8.3.1