s390/ctcm, netiucv: migrate variables to handle y2038 problem

This patch is concerned with migrating the time variables for the s390
network drivers. The changes handle the y2038 problem where timespec will
overflow in the year 2038. timespec was replaced by unsigned long and
all time variables get their values from the jiffies global variable.
This was done for the sake of speed and efficiency.

Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>