Compile serial only once

Push TARGET_WORDS_BIGENDIAN dependency to board level.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/hw/ppce500_mpc8544ds.c b/hw/ppce500_mpc8544ds.c
index 491ea7a..0901fa6 100644
--- a/hw/ppce500_mpc8544ds.c
+++ b/hw/ppce500_mpc8544ds.c
@@ -198,15 +198,17 @@
     mpic = mpic_init(MPC8544_MPIC_REGS_BASE, 1, &irqs, NULL);
 
     /* Serial */
-    if (serial_hds[0])
+    if (serial_hds[0]) {
         serial[0] = serial_mm_init(MPC8544_SERIAL0_REGS_BASE,
-                               0, mpic[12+26], 399193,
-                        serial_hds[0], 1);
+                                   0, mpic[12+26], 399193,
+                                   serial_hds[0], 1, 1);
+    }
 
-    if (serial_hds[1])
+    if (serial_hds[1]) {
         serial[0] = serial_mm_init(MPC8544_SERIAL1_REGS_BASE,
-                        0, mpic[12+26], 399193,
-                        serial_hds[0], 1);
+                                   0, mpic[12+26], 399193,
+                                   serial_hds[0], 1, 1);
+    }
 
     /* PCI */
     pci_irqs = qemu_malloc(sizeof(qemu_irq) * 4);