usb: musb: disable otg protocol support

As decided in the discussion [1] we are deleting the otg protocol
support from the musb drivers.

First this patch disables the flags for enabling the otg protocols. We
will later gradually delete the otg protocol code from the musb drivers.

[1] https://www.spinics.net/lists/linux-usb/msg167003.html



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