Merge pull request #3456 from zhao0116/spi

spi: support slave mode and master mode runtime config

components/drivers/include/drivers/spi.h

@@ -43,7 +43,7 @@ extern "C"{
 #define RT_SPI_MODE_2       (RT_SPI_CPOL | 0)              /* CPOL = 1, CPHA = 0 */
 #define RT_SPI_MODE_3       (RT_SPI_CPOL | RT_SPI_CPHA)    /* CPOL = 1, CPHA = 1 */
 
-#define RT_SPI_MODE_MASK    (RT_SPI_CPHA | RT_SPI_CPOL | RT_SPI_MSB)
+#define RT_SPI_MODE_MASK    (RT_SPI_CPHA | RT_SPI_CPOL | RT_SPI_MSB | RT_SPI_SLAVE)
 
 #define RT_SPI_BUS_MODE_SPI         (1<<0)       
 #define RT_SPI_BUS_MODE_QSPI        (1<<1)