arm64/ascend: Fix register_persistent_clock definition

ascend inclusion
category: bugfix
bugzilla: NA
CVE: NA

-------------------------------------------------

The register_persistent_clock will be called after kernel init,
so it can not be defined as __init.

Fixes: 76ab899d73d6 ("arm64/ascend: Implement the read_persistend_clock64 for aarch64")
Signed-off-by: NFang Lijun <fanglijun3@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/kernel/time.c

@@ -77,7 +77,7 @@ void read_persistent_clock64(struct timespec64 *ts)
 	__read_persistent_clock(ts);
 }
 
-int __init register_persistent_clock(clock_access_fn read_persistent)
+int register_persistent_clock(clock_access_fn read_persistent)
 {
 	/* Only allow the clockaccess functions to be registered once */
 	if (__read_persistent_clock == dummy_clock_access) {