[FS#177] ipq806x: USB3 ports fail if booted when USB3 flash drives inserted during boot time

[LEDE Bugs]

The following task has a new comment added:

FS#177 - ipq806x: USB3 ports fail if booted when USB3 flash drives inserted during boot time
User who did this - Thomas Reifferscheid (reiffert)

----------
For the records: More debug and more fixes.

withbug-inserting-after-booting.txt : http://cxg.de/_bfd3bb.htm 
withbug-inserting-prior-to-host-poweron.txt : http://cxg.de/_41ae6d.htm
fix1-inserting-after-booting.txt : http://cxg.de/_d5d5b8.htm 
fix1-inserting-prior-to-host-poweron.txt : http://cxg.de/_10b096.htm
fix2-inserting-after-booting.txt : http://cxg.de/_7da6e0.htm 
fix2-inserting-prior-to-host-poweron.txt
----------

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=177#comment2065