spi: dw: Remove Intel Thunder Bay SOC support

Remove Intel Thunder Bay specific code as the product got cancelled and
there are no end customers or users.

Signed-off-by: Nandhini Srikandan <nandhini.srikandan@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20231213060836.29203-2-nandhini.srikandan@intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>