usb: otg: ab8500-usb: drop support for ab8500 pre v2.0

AB8500 versions preceding 2.0 were only used internally by ST-Ericsson
and are not supported anymore.  This patch drops all v1.0 and v1.1
support code.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>