spi/s3c64xx: Use prepare_message() and unprepare_message()
spi/s3c64xx: Use prepare_message() and unprepare_message()

This is of very little value in itself but will be useful once the loop
iterating over the transfers is also factored out into the core.

Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs