loader: lsefi: Print more information

Printing the EFI_HANDLE pointer isn't very useful.
If the handle have a IMAGE_DEVICE_PATH or a DEVICE_PATH protocol print it.
This makes it easier to see which devices are present and what protocol they
expose.

Reviewed by: imp, tsoome
Differential Revision: https://reviews.freebsd.org/D32991
Sponsored by: Beckhoff Automation GmbH & Co. KG