MXC: use variable for irq controller base in entry-macro.S

This allows us to determine the irq controller base address
on runtime.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/plat-mxc/irq.c b/arch/arm/plat-mxc/irq.c
index 618a8b2..778ddfe 100644
--- a/arch/arm/plat-mxc/irq.c
+++ b/arch/arm/plat-mxc/irq.c
@@ -44,7 +44,7 @@
 #define AVIC_FIPNDH		0x60	/* fast int pending high */
 #define AVIC_FIPNDL		0x64	/* fast int pending low */
 
-static void __iomem *avic_base;
+void __iomem *avic_base;
 
 int imx_irq_set_priority(unsigned char irq, unsigned char prio)
 {