usb: cdnsp: Fixes incorrect value in ISOC TRB

Fixes issue with priority of operator. Operator "|" priority is
higher then "? :".
To improve the readability the operator "? :" has been replaced with
"if ()" statement.

Fixes: 3d829045 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Peter Chen <peter.chen@kernel.org>