libefi: remove efi_type()
All it is right now is some #if 0ed Solaris code that returns ENOSYS,
and is only applicable for the Solaris blockdev layer.
In the Illumos gate, there's a single user: rmformat(1);
I recommend a read of the manual as a blast from the past, but, well
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Issue #12844
Closes #12969