Allow init to mount /odm, /vendor early

Specifically we need init to relabel (/dev/device-mapper, /dev/block/dm-?)
and other files in /dev/block/* from tmpfs to dm_device and block_device
respectively.

BUG=27805372

Change-Id: I16af6e803f8e4150481137aba24d5406872f9c62
1 file changed