usb: gadget: Move CONFIG_USB_GADGET_DUALSPEED to Kconfig

Move CONFIG_USB_GADGET_DUALSPEED option to Kconfig and
make all UDC controllers select USB_GADGET_DUALSPEED:
  - add next options to Kconfig selecting USB_GADGET_DUALSPEED:
    - USB_GADGET_ATMEL_USBA
    - USB_GADGET_DWC2_OTG
    - USB_DWC3
    - CI_UDC
  - make USB_MUSB_GADGET select USB_GADGET_DUALSPEED

While at it, make some related fixes:
  - remove DUALSPEED from configs that don't enable gadget support:
    - kwb.h
    - tseries.h
  - add missing USB_GADGET option to next configs:
    - novena_defconfig
    - pcm051_rev*_defconfig
    - xfi3_defconfig

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>