[LOG] Add log level bypass support for logcat console

[LOG] Add log level bypass support for logcat console

BZ: 25924

To collect all the kernel logs and ignore the log level set in the
kernel command line for one specific console, a new console setting
is created named CON_IGNORELEVEL meaning that all the logs whatever its level
is displayed on this console. With this granularity, the consoles impacting
power consumption do not set CON_IGNORELEVEL and the one used to save kernel logs
into the file system (named logk) could set CON_IGNORELEVEL

Change-Id: If9b7a0918ddd189ffabdf87d7ad5b8a0f5281d86
Signed-off-by: Christophe Guerard <christophe.guerard@intel.com>
Reviewed-on: http://android.intel.com:8080/37736
Reviewed-by: Rocher, JeremyX <jeremyx.rocher@intel.com>
Reviewed-by: Hogander, Jouni <jouni.hogander@intel.com>
Reviewed-by: Continente, Christophe <christophe.continente@intel.com>
Reviewed-by: Tardy, Pierre <pierre.tardy@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>