mpc83xx: fix implicit declaration of function 'ft_get_prop' warnings

(cherry picked from c5bf13b02284c3204a723566a9bab700e5059659 commit)
diff --git a/board/mpc8360emds/pci.c b/board/mpc8360emds/pci.c
index 15a48dc..67cd709 100644
--- a/board/mpc8360emds/pci.c
+++ b/board/mpc8360emds/pci.c
@@ -18,6 +18,9 @@
 #include <common.h>
 #include <pci.h>
 #include <i2c.h>
+#if defined(CONFIG_OF_FLAT_TREE)
+#include <ft_build.h>
+#endif
 
 #include <asm/fsl_i2c.h>