buildroot

Makefile: do not add to targets common dependencies

Remove the rule that adds common dependencies to every target in the
"TARGETS" variable, because all those targets are packages that use the
package infrastructure or they depend on targets that use the package
infrastructure. The package infrastructure already adds common
dependencies.  Therefore, this rule is useless.

Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>