With the T4 transaction code settings being dependent on which clock is choosen to be used in SPI. All of the work had to be done at run time.
As such the statically defined ones may not work as you have no idea which clock may be actually used...
So moved the work to comput CCR into the SPI.beginTransaction code, which is only called if something like the clock speed is different than the previous call to beginTransaction
We can still convert the bit Order and Data Mode parameters into the TCR
register value as part of the SPISettings constructor code as these do
not depend on external run time settings.