Rename lib_generic/ to lib/

Now that the other architecture-specific lib directories have been
moved out of the top-level directory there's not much reason to have the
'_generic' suffix on the common lib directory.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/cpu/mpc5xxx/u-boot-customlayout.lds b/cpu/mpc5xxx/u-boot-customlayout.lds
index c08c9c9..6c80139 100644
--- a/cpu/mpc5xxx/u-boot-customlayout.lds
+++ b/cpu/mpc5xxx/u-boot-customlayout.lds
@@ -57,7 +57,7 @@
 
     cpu/mpc5xxx/start.o          (.text)
     cpu/mpc5xxx/traps.o          (.text)
-    lib_generic/crc32.o         (.text)
+    lib/crc32.o         (.text)
     arch/ppc/lib/cache.o             (.text)
     arch/ppc/lib/time.o              (.text)