usb: chipidea: imx: configure imx for ULPI phy

In order to use ULPI phy with usb host 2 and 3, we need to configure
controller register to enable ULPI features.

Each USB controller have different behaviour, so in order to avoid to have
several "swicth(data->index)" and lock/unlock, we prefer to get the index
switch and then test for features if they exist for this index.
This patch also remove useless test of reg and val. Those two values cannot
be NULL.

Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: Peter Chen <peter.chen@nxp.com>