install/lvm2: add missing kernel modules and symlinks

pvscan will not retry activating devices it could not activate in early userspace (i.e. the initramfs phase), so if we want to activate one LVM device we must activate all LVM devices. This requires including modules for all possible logical volume and etc. types (e.g. cache, writecache, RAID).

Instead of hardcoding the symlinks to /usr/bin/pdata_tools, simply search for them using find -samefile and include them all.

Fixes #251 (closed), #252 (closed)