fix(tree): correct some typos

found using codespell (https://github.com/codespell-project/codespell).

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Change-Id: I1bfa797e3460adddeefa916bb68e22beddaf6373
diff --git a/tools/fiptool/win_posix.h b/tools/fiptool/win_posix.h
index 6f0d8e6..1340640 100644
--- a/tools/fiptool/win_posix.h
+++ b/tools/fiptool/win_posix.h
@@ -149,7 +149,7 @@
  * Windows does not have the getopt family of functions, as it normally
  * uses '/' instead of '-' as the command line option delimiter.
  * These functions provide a Windows version that  uses '-', which precludes
- * using '-' as the intial letter of a program argument.
+ * using '-' as the initial letter of a program argument.
  * This is not seen as a problem in the specific instance of fiptool,
  * and enables existing makefiles to work on a Windows build environment.
  */