x86/lguest/timer: Set ->min_delta_ticks and ->max_delta_ticks

x86/lguest/timer: Set ->min_delta_ticks and ->max_delta_ticks

In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.

Make the x86 arch's lguest clockevent driver initialize these fields
properly.

This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: lguest@lists.ozlabs.org
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>