ci: remove nxp_adsp_rt500 testing for now

This platform is still pending merge in zephyr tree.

Signed-off-by: Anas Nashif <[email protected]>

Author: nashif

.github/workflows/ci.yml

@@ -1548,9 +1548,6 @@ jobs:
             xtensa-nxp_imx8m_adsp_zephyr-elf)
               PLATFORM_ARGS+="-p nxp_adsp_imx8m "
               ;;
-            xtensa-nxp_rt500_adsp_zephyr-elf)
-              PLATFORM_ARGS+="-p nxp_adsp_rt500 "
-              ;;
             xtensa-sample_controller_zephyr-elf)
               PLATFORM_ARGS+="-p qemu_xtensa "
               ;;