spi: clps711x: Refactor to use core message parsing

Convert to use default implementation of transfer_one_message() which provides
standard handling of delays and chip select management.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Mark Brown <broonie@linaro.org>