buildroot

dependencies.sh: improve the missing perl modules detection

[Thomas:
 - Check for Thread::Queue, not Thread:Queue.
 - Use 'printf' instead of 'echo -e', since printf is POSIX, but not
   'echo -e'.]

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>