init.rc: Give permissions to target_load

Give "system" permissions to target_load, so Power HAL might change
it.

Change-Id: Ied86c8e238e65ab2f9acf29f78444e899b0ab4a3
Reviewed-on: http://gerrit.pcs.mot.com/544110
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Christopher Fries <c.fries@motorola.com>
SLT-Approved: Christopher Fries <c.fries@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/587341
SLTApproved: Christopher Fries <c.fries@motorola.com>
Submit-Approved: Christopher Fries <c.fries@motorola.com>
Tested-by: Christopher Fries <c.fries@motorola.com>