ASoC:topology:fix the oops bug during topology free.

[ghost]

the topology free will cause oops:

1. becasue the snd_soc_dapm_route{} is allocated in stack, which cause
   oops duirng topology free stage. allocate it on the heap and add
   function snd_soc_tplg_route_remove() free function.
2. the string name is allocated in topology's short life buffer,
   which cause oops during topology free stage. re-allocate it on the
   heap can avoid the issue.

Signed-off-by: Wu Zhigang zhigang.wu@linux.intel.com