Make sure to load the adsp firmware after creating symlink for /vendor

Moved symlink for /vendor to occur after mounting partitions. So the loading
adsp firmware also need to be excuted after that.

Bug: 15888040
Change-Id: I5119d174ea4ca92e32cb41f365f3a0b41186b073
Permit install on bootloader HHZ12d

(Lollipop preview installs HHZ12d)

Change-Id: Ic69124b59e99244e3b82788c5c3a712421d7ce42