pinctrl: PINCTRL_K230 should depend on ARCH_CANAAN

pinctrl: PINCTRL_K230 should depend on ARCH_CANAAN

The Canaan Kendryte K230 pin controller is only present on Canaan
Kendryte K230 SoCs.  Hence add a dependency on ARCH_CANAAN, to prevent
asking the user about this driver when configuring a kernel without
Canaan Kendryte series SoC platform support.

Fixes: 545887eab6f6776a ("pinctrl: canaan: Add support for k230 SoC")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/d70279ba02a67250203744b38314f4475b3c5671.1728986052.git.geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>