Create thermald.conf symlink in /etc as well

On 3.0.101 kernel with current prebuilts, change https://github.com/CyanogenMod/android_device_motorola_qcom-common/commit/5758d26e50a334d645b8f2c43e4f136d09d8144c causes thermald failure.

"$platformid" evals to "87" and fails to create /system/etc/thermald.conf where our thermal daemon
expects it so thermald fails to start.

Change-Id: I7db4c90e05aa216d8ebce9c2aba33244c54d8395