spi: s3c64xx: Delete unused boardfile helpers

spi: s3c64xx: Delete unused boardfile helpers

The helpers to use SPI host 1 and 2 are unused in the kernel
and taking up space and maintenance hours. New systems should
use device tree and not this, so delete the code.

Cc: linux-samsung-soc@vger.kernel.org
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Sylwester Nawrocki <snawrocki@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20220118230915.157797-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>