The stm32 spi driver tries to determine the fifo size of spi devices
dynamically. However, if the spi was already configured by the bootloader
the fifo size check can become an endless loop, because the driver
expects the spi to be in its initial "after device reset" state. The
driver does already support resetting the spi device at probe, thus this
patch adds only the required device tree properties
Signed-off-by: Tobias Schramm <t.schramm@xxxxxxxxxxx>