S390: Don't tell guest we're updating config space

S390: Don't tell guest we're updating config space

Currently we always set the "config space changed" bit to 1 when triggering
any virtio interrupt. While that worked in 2.6.27, newer kernels interpret
that value as "only the config space changed and nothing else happened".

Since we usually trigger interrupts to tell the guest that something did
happen, we just not tell it the config space changed for now until we
implement the correct callback for that.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
(cherry picked from commit 86f3dba6518bd5fd106e1cf3f36dafda41ff377b)