MX28: extend print_cpuinfo() to use chip information

The information now is gathered from HW_DIGCTL_CHIPID register and
includes the chip modem and revision on the output.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
diff --git a/arch/arm/include/asm/arch-mx28/regs-digctl.h b/arch/arm/include/asm/arch-mx28/regs-digctl.h
index 9a63594..247da6e 100644
--- a/arch/arm/include/asm/arch-mx28/regs-digctl.h
+++ b/arch/arm/include/asm/arch-mx28/regs-digctl.h
@@ -152,4 +152,8 @@
 };
 #endif
 
+/* Product code identification */
+#define HW_DIGCTL_CHIPID_MASK	(0xffff << 16)
+#define HW_DIGCTL_CHIPID_MX28	(0x2800 << 16)
+
 #endif /* __MX28_REGS_DIGCTL_H__ */