WS cleanup: remove trailing white space

Signed-off-by: Wolfgang Denk <wd@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/README.distro b/doc/README.distro
index c4f041c..fa8cec1 100644
--- a/doc/README.distro
+++ b/doc/README.distro
@@ -233,7 +233,7 @@
   the DTB with a different DTB. fdtfile will automatically be set for you if
   it matches the format ${soc}-${board}.dtb which covers most 32 bit use cases.
   AArch64 generally does not match as the Linux kernel put the dtb files under
-  SoC vendor directories. 
+  SoC vendor directories.
 
 ramdisk_addr_r: