Revert "usb: dwc3: Support EBC feature of DWC_usb31"

This reverts commit 398aa9a7.

The update to the gadget API to support EBC feature is incomplete. It's
missing at least the following:
 * New usage documentation
 * Gadget capability check
 * Condition for the user to check how many and which endpoints can be
   used as "fifo_mode"
 * Description of how it can affect completed request (e.g. dwc3 won't
   update TRB on completion -- ie. how it can affect request's actual
   length report)

Let's revert this until it's ready.

Fixes: 398aa9a7

 ("usb: dwc3: Support EBC feature of DWC_usb31")
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/3042f847ff904b4dd4e4cf66a1b9df470e63439e.1707441690.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>