Using of alternate SPI

Hi,
Please take a look - this platform has additional SPI buses.
https://github.com/stm32duino/wiki/wiki/API#spi
When we are using an ISP OLED, on such platforms, we can direct the AD9833 to an alternative bus
I am doing tests, maybe you can implement better in code by a #define

At beginning of AD9833.cpp
/* Configure SPI3 of STM32 MOSI: PC12, MISO: PC11, SCLK: PC10 */
SPIClass SPIX(PC12, PC11, PC10);

Replace the SPI. with SPIX. used in 4 commands