usb: musb: remove some register access wrapper functions

The following wrappers were defined because of Blackfin support. Now
Blackfin support is removed, these wrappers are no longer needed, so
remove them.

	musb_write_txfifosz
	musb_write_txfifoadd
	musb_write_rxfifosz
	musb_write_rxfifoadd
	musb_write_ulpi_buscontrol
	musb_read_txfifosz
	musb_read_txfifoadd
	musb_read_rxfifosz
	musb_read_rxfifoadd
	musb_read_ulpi_buscontrol
	musb_read_hwvers

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