KVM: arm64: Use ktime_get_snapshot_id() to retrieve CLOCK_BOOTTIME

KVM: arm64: Use ktime_get_snapshot_id() to retrieve CLOCK_BOOTTIME

ktime_get_snapshot() is replaced by ktime_get_snapshot_id() which allows to
request a particular CLOCK ID to be captured along with the clocksource
counter.

Convert the tracing mechanism over and use the new
system_time_snapshot::systime field, which holds the system timestamp
selected by the CLOCK ID argument.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Arthur Kiyanovski <akiyano@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260529195557.174373054@kernel.org