Use no_timer_check with soft-qemu

The Linux kernel timer check not working properly
when the hypervisor's thread preempted by the host CPU scheduler.

The timer check is automatically disabled with other types
of hypervisors including the hardware accelerated kvm,
but timer_check is not disabled when qemu used without hardware acceleration.

This issue is frequently mischaracterized as an SSH connectivity issue and
causes rechecks and occasional boot failures.

This change adds no_timer_check kernel parameter when we are using
uec images with qemu.

Closes-Bug: #1312199
Change-Id: I3cfdfe9048fe219fc12cdac8a399b496f237e55e
Merge "Use no_timer_check with soft-qemu"