Add basic errno support.

Needed for hash table support; probably useful in a lot of other
places as well.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/lib/Makefile b/lib/Makefile
index c45f07c..c26536d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -37,6 +37,7 @@
 COBJS-y += ctype.o
 COBJS-y += display_options.o
 COBJS-y += div64.o
+COBJS-y += errno.o
 COBJS-$(CONFIG_GZIP) += gunzip.o
 COBJS-$(CONFIG_LMB) += lmb.o
 COBJS-y += ldiv.o