cosmetic: Fix spelling and whitespace errors

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
diff --git a/doc/uImage.FIT/source_file_format.txt b/doc/uImage.FIT/source_file_format.txt
index f8e27ed..18d2aed 100644
--- a/doc/uImage.FIT/source_file_format.txt
+++ b/doc/uImage.FIT/source_file_format.txt
@@ -262,7 +262,7 @@
   - loadables : Unit name containing a list of additional binaries to be
     loaded at their given locations.  "loadables" is a comma-separated list
     of strings. U-Boot will load each binary at its given start-address and
-    may optionaly invoke additional post-processing steps on this binary based
+    may optionally invoke additional post-processing steps on this binary based
     on its component image node type.
   - compatible : The root compatible string of the U-Boot device tree that
     this configuration shall automatically match when CONFIG_FIT_BEST_MATCH is