[POWERPC] 4xx: Add 405EX CPU type needed for EMAC support on Kilauea

For EMAC support, 405EX needs to be defined to enable the corresponding
EMAC features (IBM_NEW_EMAC_EMAC4, etc.).
Signed-off-by: NStefan Roese <sr@denx.de>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

arch/powerpc/platforms/40x/Kconfig

@@ -27,6 +27,7 @@ config KILAUEA
 	bool "Kilauea"
 	depends on 40x
 	default n
+	select 405EX
 	help
 	  This option enables support for the AMCC PPC405EX evaluation board.
 
@@ -100,6 +101,11 @@ config 405GP
 config 405EP
 	bool
 
+config 405EX
+	bool
+	select IBM_NEW_EMAC_EMAC4
+	select IBM_NEW_EMAC_RGMII
+
 config 405GPR
 	bool