The B2 board has different IO pins here for these two pins

Saves power and prevents heating

todo:
analogInputToDigitalPin(p)
digitalPinHasPWM(p)

Fixed the Serial2 object to use the new correct pins, plus made Serial8 only valid for T4 B1 (not B2).

Also I defined IO pins for the six signals associated with the SD Card slot.

I have tested these both as IO pins and now as SPI2

Moved from my flexio_t4 library.
Libary was updated to see if already defined before it now defines it.

Code from :: https://community.nxp.com/thread/389002
Name the fault dump info
New weak to override :: HardFault_HandlerC()

Allow the user to call setTX with the one hardware pin, and hopefully allow them to turn on Open Drain mode or turn it back off.  I don't currently have any test cases that use this, so not sure how well it works.

Page 982.
Fixes https://forum.pjrc.com/threads/54711-Teensy-4-0-First-Beta-Test?p=196233&viewfull=1#post196233
- maybe this is needed for T3x, too? too late here to check this now.

The FlexIO registers are 32 bits, the masks were all setup for 16 bits so the high word of registers were not updated