binman: Update entry help for files-align

Regenerate the entry documentation, which step was missed when the
files-align feature was added.

Fixes: 6eb9932668f ("binman: Support alignment of files")

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/README.entries b/tools/binman/README.entries
index 999b776..7cca030 100644
--- a/tools/binman/README.entries
+++ b/tools/binman/README.entries
@@ -302,6 +302,7 @@
     - files-compress: Compression algorithm to use:
         none: No compression
         lz4: Use lz4 compression (via 'lz4' command-line utility)
+    - files-align: Align each file to the given alignment
 
 This entry reads a number of files and places each in a separate sub-entry
 within this entry. To access these you need to enable device-tree updates