buildroot

get-developers: use --cc instead of --to for developers

Output of get-developers script in our manual uses --cc for developers,
but actual output of get-developers script uses --to. This patch makes
code consistent with documentation, by using --cc for developers.

Signed-off-by: Rahul Bedarkar <rahul.bedarkar@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>