common & fw-update: Improving Logs (lg2)

This commit corrects the severity level of logs and also formats the
message string, fixing the ill-defined message string of the logs as
mentioned in the anti-pattern document [1]. Additionally, based on the
requirement this commit adds more debug information to logs.

[1]: https://github.com/openbmc/docs/blob/master/anti-patterns.md#ill-defined-data-structuring-in-lg2-message-strings



Change-Id: I1481c025b6dc6a9200a13de38a4fe55b81bb25ea
Signed-off-by: Riya Dixit <riyadixitagra@gmail.com>