ARM: zynq: Add support for SOC_BUS

Provide information through SOC_BUS to user space.
Silicon revision is provided through devcfg device.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h
index b097844..f652f0a 100644
--- a/arch/arm/mach-zynq/common.h
+++ b/arch/arm/mach-zynq/common.h
@@ -24,6 +24,7 @@
 extern void zynq_slcr_system_reset(void);
 extern void zynq_slcr_cpu_stop(int cpu);
 extern void zynq_slcr_cpu_start(int cpu);
+extern u32 zynq_slcr_get_device_id(void);
 
 #ifdef CONFIG_SMP
 extern void secondary_startup(void);