usb: phy: ab8500-usb: fix eye diagram for ab8500 v2.0

AB8500 v2.0 has eye diagram issues when drawing more than 100mA from
VBUS.  Force charging current to 100mA in case of standard host.

Signed-off-by: Sakethram Bommisetti <sakethram.bommisetti@stericsson.com>
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>