The SPI0 platform population function was taking a custom
gpio setup callback but the only user pass NULL as
argument so drop this argument.

Cc: linux-samsung-soc@vger.kernel.org
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Sylwester Nawrocki <snawrocki@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: NSam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20220118230915.157797-2-linus.walleij@linaro.orgSigned-off-by: NMark Brown <broonie@kernel.org>