clang-tidy: Enable readability checks on repo

The readability-* checks in Clang-Tidy focus on improving code
readability by enforcing guidelines and suggesting improvements
that can enhance the clarity and maintainability of C++ code.

Tested: Build and unit tests passed successfully.

Change-Id: Icf996f860bc763e0aebd095d8f50c67813e2395e
Signed-off-by: Jayanth Othayoth <ojayanth@gmail.com>