arm: omap: irq: remove unused macro

no functional changes.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/irq.c

@@ -42,8 +42,6 @@
 #define INTC_MIR_SET0		0x008c
 #define INTC_PENDING_IRQ0	0x0098
 #define INTC_ILR0		0x0100
-/* Number of IRQ state bits in each MIR register */
-#define IRQ_BITS_PER_REG	32
 
 #define OMAP2_IRQ_BASE		OMAP2_L4_IO_ADDRESS(OMAP24XX_IC_BASE)
 #define OMAP3_IRQ_BASE		OMAP2_L4_IO_ADDRESS(OMAP34XX_IC_BASE)