powerpc64: do tc_init(9) before cpu_startclock()

[Scott Cheloha]

In the future, the clock interrupt will need a working timecounter to
accurately reschedule itself.

Move tc_init(9) up before cpu_startclock().

(I can't test this but it seems correct.)

ok?

Index: clock.c
===================================================================
RCS file: /cvs/src/sys/arch/powerpc64/powerpc64/clock.c,v
retrieving revision 1.3
diff -u -p -r1.3 clock.c
--- clock.c     23 Feb 2021 04:44:31 -0000      1.3
+++ clock.c     25 May 2022 00:05:59 -0000
@@ -57,6 +57,9 @@ tb_get_timecount(struct timecounter *tc)
 void
 cpu_initclocks(void)
 {
+       tb_timecounter.tc_frequency = tb_freq;
+       tc_init(&tb_timecounter);
+
        tick_increment = tb_freq / hz;
 
        stathz = 100;
@@ -68,9 +71,6 @@ cpu_initclocks(void)
        evcount_attach(&stat_count, "stat", NULL);
 
        cpu_startclock();
-
-       tb_timecounter.tc_frequency = tb_freq;
-       tc_init(&tb_timecounter);
 }
 
 void