env: Drop env_crc_update()

This function is not defined or used in U-Boot. Drop it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/include/environment.h b/include/environment.h
index c740d5a..27c0fee 100644
--- a/include/environment.h
+++ b/include/environment.h
@@ -265,9 +265,6 @@
 
 extern struct hsearch_data env_htab;
 
-/* Function that updates CRC of the enironment */
-void env_crc_update(void);
-
 /* Look up the variable from the default environment */
 char *env_get_default(const char *name);