powerpc: keymile: Add a check for the PIGGY debug board

Check the presence of the PIGGY on the keymile boards mgcoge,
mgsuvd and kmeter1. If the PIGGY is not present, dont register
this Ethernet device.

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/include/configs/mgsuvd.h b/include/configs/mgsuvd.h
index fca2e55..b862130 100644
--- a/include/configs/mgsuvd.h
+++ b/include/configs/mgsuvd.h
@@ -211,6 +211,15 @@
 #define CONFIG_ENV_OFFSET_REDUND	(CONFIG_ENV_OFFSET+CONFIG_ENV_SECT_SIZE)
 #define CONFIG_ENV_SIZE_REDUND	(CONFIG_ENV_SIZE)
 
+/*
+ * How to get access to the slot ID.  Put this here to make it easy
+ * to modify in a centralized location.  This is used in the HDLC
+ * driver to set the MAC.
+*/
+#define CONFIG_SYS_SLOT_ID_BASE		CONFIG_SYS_PIGGY_BASE
+#define CONFIG_SYS_SLOT_ID_OFF		(0x07)	/* register offset */
+#define CONFIG_SYS_SLOT_ID_MASK		(0x3f)	/* mask for slot ID bits */
+
 /*-----------------------------------------------------------------------
  * Cache Configuration
  */