Add B580 to README (#4874)

Signed-off-by: Pavel Chekin <[email protected]>

Author: pbchekin

.github/README.md

@@ -14,6 +14,7 @@ Intel® XPU Backend for Triton\* is a out of tree backend module for [Triton](ht
   * [Intel® Data Center GPU Max Series](https://www.intel.com/content/www/us/en/products/details/discrete-gpus/data-center-gpu/max-series.html)
   * [Intel® Data Center Flex Series](https://www.intel.com/content/www/us/en/products/details/discrete-gpus/data-center-gpu/flex-series.html)
   * [Intel® Arc A770](https://www.intel.com/content/www/us/en/products/sku/229151/intel-arc-a770-graphics-16gb/specifications.html)
+  * [Intel® Arc B580](https://www.intel.com/content/www/us/en/products/sku/241598/intel-arc-b580-graphics/specifications.html)
 * GPU Drivers:
   * Latest [Long Term Support (LTS) Release](https://dgpu-docs.intel.com/driver/installation.html)
   * Latest [Rolling Release](https://dgpu-docs.intel.com/driver/installation-rolling.html)