[PATCH] ppc64: fix time syscall

ppc64 has its own version of sys_time. It looks pretty scary, touching
a whole bunch of variables without any locking or memory ordering.

In fact, a recent bugreport has shown it can actually go backwards. Time
to remove it and just use the generic sys_time, which is implemented on
top of do_gettimeofday.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>