usb: USB_FOTG210 should depend on ARCH_GEMINI

The Faraday Technology FOTG210 USB2 Dual Role Controller is only present
on Cortina Systems Gemini SoCs.  Hence add a dependency on ARCH_GEMINI,
to prevent asking the user about its drivers when configuring a kernel
without Cortina Systems Gemini SoC support.

Fixes: 1dd33a9f ("usb: fotg210: Collect pieces of dual mode controller")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/a989b3b798ecaf3b45f35160e30e605636d66a77.1669044086.git.geert+renesas@glider.be


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>