clocksource: dbx500: convert to clocksource_register_hz()

Convert clocksource_dbx500_prcmu to use clocksource_register_hz.

Cc: Thomas Gleixner <[e-mail]>
Cc: Mattias Wallin <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Signed-off-by: Yong Zhang <[e-mail]>
Signed-off-by: John Stultz <[e-mail]>

drivers/clocksource/clksrc-dbx500-prcmu.c

···
 	.name		= "dbx500-prcmu-timer",
 	.rating		= 300,
 	.read		= clksrc_dbx500_prcmu_read,
-	.shift		= 10,
 	.mask		= CLOCKSOURCE_MASK(32),
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
···
 	setup_sched_clock(dbx500_prcmu_sched_clock_read,
 			 32, RATE_32K);
 #endif
-	clocksource_calc_mult_shift(&clocksource_dbx500_prcmu,
-				    RATE_32K, SCHED_CLOCK_MIN_WRAP);
-	clocksource_register(&clocksource_dbx500_prcmu);
+	clocksource_register_hz(&clocksource_dbx500_prcmu, RATE_32K);
 }