ARC: Interrupt Handling

This contains:
-bootup arch IRQ init: init_IRQ(), arc_init_IRQ()
-generic IRQ subsystem glue: arch_do_IRQ()
-basic IRQ chip setup for in-core intc

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

arch/arc/include/asm/arcregs.h

@@ -11,6 +11,9 @@
 
 #ifdef __KERNEL__
 
+/* Build Configuration Registers */
+#define ARC_REG_VECBASE_BCR	0x68
+
 /* status32 Bits Positions */
 #define STATUS_H_BIT		0	/* CPU Halted */
 #define STATUS_E1_BIT		1	/* Int 1 enable */