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

Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml

@@ -72,8 +72,6 @@ properties:
           - const: snps,dw-apb-ssi
       - description: Intel Keem Bay SPI Controller
         const: intel,keembay-ssi
-      - description: Intel Thunder Bay SPI Controller
-        const: intel,thunderbay-ssi
       - description: Intel Mount Evans Integrated Management Complex SPI Controller
         const: intel,mountevans-imc-ssi
       - description: AMD Pensando Elba SoC SPI Controller