usb: musb: remove unused members in struct musb_hdrc_config

The following members in struct musb_hdrc_config are not used,
so remove them.

soft_con
utm_16
big_endian
mult_bulk_tx
mult_bulk_rx
high_iso_tx
high_iso_rx
dma
dma_channels
dyn_fifo_size
vendor_ctrl
vendor_stat
vendor_req
dma_req_chan
musb_hdrc_eps_bits

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>