Support all SPI modes

[platenyponchet]

Hardware: ESP13
Core Version: 2.1.0-rc2

How can i change the SPI data mode? The setDataMode is TODO.

[Links2004]

SPI mode 0 + 1 are possible with the ESP.
SPI mode 2 + 3 are not possible with the Hardware SPI.

https://github.com/esp8266/Arduino/blob/master/doc/libraries.md#spi

[igrr]

@Links2004 check this out: https://github.com/UncleRus/esp-open-rtos/blob/core/spi/core/esp_spi.c#L73-L86