Delay UL powerdown if BAM is in polling mode

Reviewed-on: http://gerrit.pcs.mot.com/548359
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Igor Kovalenko <cik009@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Reviewed-by: Alexander Filonenko <alexf@motorola.com>
SLT-Approved: Christopher Fries <c.fries@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

idea is taken here -
https://github.com/franciscofranco/hammerhead/commit/e6c72d47695e45aacbc56c0c9700654a623e9d80