REVERT ME: dma-buf: Add more info to debugfs hooks.

Make the bufinfo file list processes which have open fds on
a dma-buf in addition to just the devices which have attachments.
Use the dev_name() func for attached devices as well.

Change-Id: Ibbb0efe8de4a44d40b94040c6ab02e349d5dea25
Signed-off-by: Riley Andrews <riandrews@google.com>