s390x/css: update css_adapter_interrupt

s390x/css: update css_adapter_interrupt

Let's use the new inject_airq callback of flic to inject adapter
interrupts. For kvm case, if the kernel flic doesn't support the new
interface, the irq routine remains unchanged. For non-kvm case,
qemu-flic handles the suppression process.

Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: Fei Li <sherrylf@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>