staging: dwc2: toggle periodic debugging output separately

This adds a config option USB_DWC2_DEBUG_PERIODIC that allows debugging
output be suppressed for periodic transfers. This helps when debugging
non-periodic transfers while there are also periodic transfers going on
(both to make the debug output less polluted and to prevent all CPU time
going to debug messages).

In addition, a debug message from dwc2_hcd_is_status_changed is removed
entirely, since it often floods the log regardless of periodic
transfers.

Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl>
Cc: Paul Zimmerman <Paul.Zimmerman@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>