usb: dwc3: remove the call trace of USBx_GFLADJ

layerscape board sometimes reported some usb call trace, that is due to
kernel sent LPM tokerns automatically when it has no pending transfers
and think that the link is idle enough to enter L1, which procedure will
ask usb register has a recovery,then kernel will compare USBx_GFLADJ and
set GFLADJ_30MHZ, GFLADJ_30MHZ_REG until GFLADJ_30MHZ is equal 0x20, if
the conditions were met then issue occur, but whatever the conditions
whether were met that usb is all need keep GFLADJ_30MHZ of value is 0x20
(xhci spec ask use GFLADJ_30MHZ to adjust any offset from clock source
that generates the clock that drives the SOF counter, 0x20 is default
value of it)That is normal logic, so need remove the call trace.

Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>