usb: musb: Remove unused local variable dma, urb, offset

Remove unused function argument struct dma_controller *dma,
struct urb *urb and u32 offset from musb_tx_dma_set_mode_mentor.

Signed-off-by: Saurav Girepunje <saurav.girepunje@gmail.com>
Link: https://lore.kernel.org/r/20210508170317.24403-2-saurav.girepunje@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>