drivers: xen: events: fix build issues with disabled Xen HVC

Some setups do not use Xen hypervisor console for logging, e.g. they
use emulated PL011 hardware or shared peripherals (real UART). In such
cases Xen HVC will be disabled on a build time and will cause issues in
current driver implementation.

This commit fixes build issues in Xen event channel driver, caused
by absense of console event channel, that is not available when console
config is disabled. Now console related code will be removed when
Xen HVC is turned off.

Signed-off-by: Dmytro Firsov <dmytro_firsov@epam.com>
Reviewed-by: Anastasiia Lukianenko <vicooodin@gmail.com>
Reviewed-by: Anastasiia Lukianenko <vicooodin@gmail.com<mailto:vicooodin@gmail.com>>
Signed-off-by: Dmytro Firsov <dmytro_firsov@epam.com<mailto:dmytro_firsov@epam.com>>