s390/net: remove pm support from iucv drivers

Commit 39421627 ("s390: remove broken hibernate / power management support")
removed support for ARCH_HIBERNATION_POSSIBLE on s390.
So drop the unused pm ops from the iucv drivers.

CC: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>