spi: clps711x: Driver refactor

This is a complex patch for refactoring CLPS711X SPI driver.
This change adds devicetree support and removes board support.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>