kernel headers: Update comparison logic

Update comparison logic used to figure out the headers
that need to be added or removed from the corresponding
blueprint file.

Change-Id: I1f8eeea9750074d57868593a9693c016644e3682
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Signed-off-by: Naitik Bharadiya <bharad@codeaurora.org>