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: Ic3b71f8cc63e423ca725ce0480fa6686340207c9
Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>