spi_nxp_lpspi: Remove SDK items from header file

Remove SDK types and defines from header file.

And since now the common file is the only consumer of SDK header, move
that include there.

Also rename the tristate boolean to be more clean about what it does
rather than trying to be similar to the SDK config name.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>