clocksource/drivers/arm_arch_timer: Advertise 56bit timer to the core code

Proudly tell the code code that we have a timer able to handle
56 bits deltas.

Signed-off-by: Marc Zyngier <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Daniel Lezcano <[e-mail]>

drivers/clocksource/arm_arch_timer.c

···
 
 	clk->set_state_shutdown(clk);
 
-	clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
+	clockevents_config_and_register(clk, arch_timer_rate, 0xf, CLOCKSOURCE_MASK(56));
 }
 
 static void arch_timer_evtstrm_enable(int divider)