ppc4xx: Remove now unused CONFIG_UART1_CONSOLE

CONFIG_UART1_CONSOLE was a PPC4xx specific implementation and is now
removed since the move from the 4xx UART driver to the common NS16550
UART driver. Let's remove all references to this define now.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/common/serial.c b/common/serial.c
index dbc74bd..25b235a 100644
--- a/common/serial.c
+++ b/common/serial.c
@@ -54,10 +54,7 @@
 #else
 #error "Bad CONFIG_CONS_INDEX."
 #endif
-#elif defined(CONFIG_UART1_CONSOLE)
-		return &serial1_device;
-#else
-		return &serial0_device;
+	return &serial0_device;
 #endif
 #elif defined(CONFIG_MPC512X)
 #if (CONFIG_PSC_CONSOLE == 3)