selftests/eeh: Skip ahci adapters

The ahci driver doesn't support error recovery, and if your root
filesystem is attached to it the eeh-basic.sh test will likely kill
your machine.

So skip any device we see using the ahci driver.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200326061144.2006522-1-mpe@ellerman.id.au