remove some timer device cases

Signed-off-by: Nyama <yama@redhat.com>

qemu/tests/cfg/timerdevice.cfg

@@ -94,6 +94,7 @@
                         - without_host_load:
                         - with_host_load:
                             only Linux
+                            only clksource_kvm-clock..clock_host
                             login_timeout = 600
                             timerdevice_host_load_cmd = "for (( I=0; I<`grep processor /proc/cpuinfo"
                             timerdevice_host_load_cmd += " | wc -l`; I++ )); do taskset -c $I /bin/bash -c"
@@ -102,6 +103,7 @@
                     variants:
                         - reboot_immediately:
                         - reboot_after_sleep:
+                            only with_host_load
                             timerdevice_sleep_time = 3600
         - tscsync:
             only Linux