spi: Add Qualcomm QUP SPI controller support

Qualcomm Universal Peripheral (QUP) core is an AHB slave that
provides a common data path (an output FIFO and an input FIFO)
for serial peripheral interface (SPI) mini-core. SPI in master
mode supports up to 50MHz, up to four chip selects, programmable
data path from 4 bits to 32 bits and numerous protocol variants.

Cc: Alok Chauhan <alokc@codeaurora.org>
Cc: Gilad Avidov <gavidov@codeaurora.org>
Cc: Kiran Gunda <kgunda@codeaurora.org>
Cc: Sagar Dharia <sdharia@codeaurora.org>
Cc: dsneddon@codeaurora.org
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Mark Brown <broonie@linaro.org>