s390/time: Remove read_boot_clock64()

read_boot_clock64() was replaced by read_persistent_wall_and_boot_offset()
so remove it.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-18-pasha.tatashin@oracle.com

arch/s390/kernel/time.c

@@ -239,19 +239,6 @@ void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time,
 	*boot_offset = timespec64_sub(*wall_time, boot_time);
 }
 
-void read_boot_clock64(struct timespec64 *ts)
-{
-	unsigned char clk[STORE_CLOCK_EXT_SIZE];
-	__u64 delta;
-
-	delta = initial_leap_seconds + TOD_UNIX_EPOCH;
-	memcpy(clk, tod_clock_base, 16);
-	*(__u64 *) &clk[1] -= delta;
-	if (*(__u64 *) &clk[1] > delta)
-		clk[0]--;
-	ext_to_timespec64(clk, ts);
-}
-
 static u64 read_tod_clock(struct clocksource *cs)
 {
 	unsigned long long now, adj;