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>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://msgid.link/r/20231213060836.29203-3-nandhini.srikandan@intel.com


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