pinctrl: starfive: Allow compile testing on other platforms

pinctrl: starfive: Allow compile testing on other platforms

Always descent to drivers/pinctrl/starfive/ because limiting it with
SOC_STARFIVE is redundant since its Makefile doesn't build anything if
no Starfive-specific pin control Kconfig options are enabled.  This
allows compile testing on other architectures with allyesconfig.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Acked-by: Hal Feng <hal.feng@starfivetech.com>
Link: https://lore.kernel.org/20250611-pinctrl-const-desc-v2-1-b11c1d650384@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>