arm: mx6: tqma6: Fix USB and add other filesystems

This patch fixes the USB EHCI support on the TQMa6 SoM. Additionally
some filesystems are added, included the generic FS commands (e.g.
ls...).

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Markus Niebel <Markus.Niebel@tq-group.com>
Cc: Stefano Babic <sbabic@denx.de>
Acked-By: Markus Niebel <Markus.Niebel@tq-group.com>