usb/gadget/snps_udc_core: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

If the probe fails, udc_remove() will not be called, so there is no
reason to make del_timer_sync() calls conditional. As a result, use of
the .data field can be dropped, in support of making removing this field
entirely from struct timer_list.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Raviteja Garimella <raviteja.garimella@broadcom.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>