Fix spelling mistakes using codespell

This commit corrects various spelling mistakes throughout the
repository. The corrections were made automatically using `codespell`[1]
tool.

[1]: https://github.com/codespell-project/codespell

Change-Id: I8870ce249bba3373e85f82903cfa875d6a7c8725
Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
diff --git a/image_verify.cpp b/image_verify.cpp
index 52ef3ef..4d874b4 100644
--- a/image_verify.cpp
+++ b/image_verify.cpp
@@ -226,7 +226,7 @@
         // Either BMC images or optional images shall be valid
         assert(valid || optionalImagesValid);
 
-        debug("Successfully completed Signature vaildation.");
+        debug("Successfully completed Signature validation.");
         return true;
     }
     catch (const InternalFailure& e)