mfd: ab8500-debugfs: Add interrupt debug

This patch adds an entry in debugfs to check number of interrupts
from the AB.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
Reviewed-by: Rabin VINCENT <rabin.vincent@stericsson.com>
diff --git a/drivers/mfd/ab8500-core.c b/drivers/mfd/ab8500-core.c
index d228697..05a7af4 100644
--- a/drivers/mfd/ab8500-core.c
+++ b/drivers/mfd/ab8500-core.c
@@ -521,6 +521,7 @@
 			int virq = ab8500_irq_get_virq(ab8500, line);
 
 			handle_nested_irq(virq);
+			ab8500_debug_register_interrupt(line);
 			value &= ~(1 << bit);
 
 		} while (value);