ASoC: topology: Clean up route loading

Instead of using very long macro name, assign it to shorter variable
and use it instead. While doing that, we can reduce multiple if checks
using this define to one.

Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Link: https://lore.kernel.org/r/20240603102818.36165-5-amadeuszx.slawinski@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>