usb: core: Remove helper APIs returning dcba dma address

Since dcba dma address is not required by class driver
therefore remove the API definitions.

Change-Id: I2623cf3bf406ca0d47ea2549b5163d9e9b7351a1
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Mayank Rana <mrana@codeaurora.org>