docs: Update path that mentions deprecated.rst

Missed in commit f3478392 "docs: Move deprecation, build
and license info out of system/"

Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20210723065828.1336760-1-maozhongyi@cmss.chinamobile.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/configure b/configure
index 69cef68..79e2ddc 100755
--- a/configure
+++ b/configure
@@ -5230,7 +5230,7 @@
 
 if test -n "${deprecated_features}"; then
     echo "Warning, deprecated features enabled."
-    echo "Please see docs/system/deprecated.rst"
+    echo "Please see docs/about/deprecated.rst"
     echo "  features: ${deprecated_features}"
 fi