dev: gcdb: Add panel signature for Novatek 720p & 1080p panels

Add panel signature field to the panel header files so the
autodetection feature can read the panel signature and
compare to the value in the header to determine if the panel
is attached to the target.

Change-Id: I4ed4c2ee716a9a64f30c12f7eb9c6d03298c2f55
2 files changed