usb: dwc3-msm: Fix maximum_speed determination

Currently driver is setting the user override speed to
maximum speed by checking if override speed is less than
the maximum speed. But this check will fail if the maximum
speed supported by the controller is super-speed and user
is trying to set it to super-speed from a lower speed. Fix
this by checking if override speed is equal to or less than
maximum speed.

Change-Id: Id71cf163548e213ec0180d7f3107395feed2f483
Signed-off-by: Pratham Pratap <prathampratap@codeaurora.org>