waf: added -Werror=cast-align

Tools/ardupilotwaf/boards.py

@@ -180,7 +180,6 @@ class Board:
             '-Wall',
             '-Wextra',
             '-Wpointer-arith',
-            '-Wcast-align',
             '-Wundef',
             '-Wno-unused-parameter',
             '-Wno-missing-field-initializers',
@@ -188,6 +187,7 @@ class Board:
             '-Wno-redundant-decls',
             '-Wno-unknown-pragmas',
             '-Wno-expansion-to-defined',
+            '-Werror=cast-align',
             '-Werror=attributes',
             '-Werror=format-security',
             '-Werror=format-extra-args',