nir/spirv: Add support for device groups

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>

src/compiler/shader_enums.c

@@ -232,6 +232,7 @@ gl_system_value_name(gl_system_value sysval)
      ENUM(SYSTEM_VALUE_GLOBAL_INVOCATION_ID),
      ENUM(SYSTEM_VALUE_WORK_GROUP_ID),
      ENUM(SYSTEM_VALUE_NUM_WORK_GROUPS),
+     ENUM(SYSTEM_VALUE_DEVICE_INDEX),
      ENUM(SYSTEM_VALUE_VIEW_INDEX),
      ENUM(SYSTEM_VALUE_VERTEX_CNT),
    };