phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround

If we configure the da8xx OTG phy in OTG mode, neither device or host
mode will work. That is because the PHY is not able to detect and notify
the driver that value of ID pin changed.
To work despite this hardware limitation, the da8xx glue implement a
workaround.
But to work, the workaround require the VBUS sense and the session end
comparator to enabled.
Enable them if the phy is configured in OTG mode.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>