rsyslog: enable more basic features

Enable all of the basic modules that don't require any dependencies.
Reasoning is simple, if someone wants rsyslog over a smaller busybox
logger or sysklogd it's probably looking for features.

[Thomas: fix indentation.]

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>