This change affects:
- both PEM and DER files, since they contain the same public key
only in different formats
- "ec_pub.comp.pem" since it's the same as "ec_pub.pem" but in
compressed format
The makefile was also updated accordingly to reflect these
dependencies.
Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>