fotg210-udc: Handle PCLK

This adds optional handling of the peripheral clock PCLK.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221114115201.302887-3-linus.walleij@linaro.org


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