SPI: add CSR SiRFprimaII SPI controller driver

SPI: add CSR SiRFprimaII SPI controller driver

CSR SiRFprimaII has two SPIs (SPI0 and SPI1). Features:
* Master and slave modes
* 8-/12-/16-/32-bit data unit
* 256 bytes receive data FIFO and 256 bytes transmit data FIFO
* Multi-unit frame
* Configurable SPI_EN (chip select pin) active state
* Configurable SPI_CLK polarity
* Configurable SPI_CLK phase
* Configurable MSB/LSB first

Signed-off-by: Zhiwu Song <zhiwu.song@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>