jjb: lttng-modules: refactor triggers

jjb: lttng-modules: refactor triggers

Refactor triggers for lttng-modules kernel buils.

'(cross)build-vanilla':
  - hourly check for lttng-modules commits
  - daily (22:00) check for new kernel tags

'fullbuild-vanilla':
  - friday at midnight check for lttng-modules commits

'build-{UBUNTU}':
  - hourly check for lttng-modules commits
  - saturday at midnight check for new ubuntu kernel tags

'build-rt':
  - hourly check for lttng-modules commits
  - sunday at midnight check for new rt kernel tags

Change-Id: I9b827d926f89c81f49e6689b3c12f9688ae7ede4
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>