libvorbis: use BR2_SOFT_FLOAT to set default for tremor

Use BR2_SOFT_FLOAT to set default for tremor instead of hardcoded arch list.

package/libvorbis/Config.in

@@ -17,7 +17,7 @@ config BR2_PACKAGE_LIBVORBIS
 
 config BR2_PACKAGE_LIBVORBIS_TREMOR
 	bool "use fixed point implementation (tremor)
-	default y if BR2_arm || BR2_avr32
+	default y if BR2_SOFT_FLOAT
 	default n
 	depends on BR2_PACKAGE_LIBVORBIS
 	help