debug: remove some event channel info from the 'i' and 'q' debug keys

debug: remove some event channel info from the 'i' and 'q' debug keys

The 'i' key would always use VCPU0's selector word when printing the
event channel state. Remove the incorrect output as a subsequent
change will add the (correct) information to the 'e' key instead.

When dumping domain information, printing the state of the VIRQ_DEBUG
port is redundant -- this information is available via the 'e' key.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>