[MIPS] unexport rtc_mips_set_time()

No users for the rtc_mips_set_time() routine exist outside of the
core kernel code. Therefore, EXPORT_SYMBOL(rtc_mips_set_time) is
useless, and this patch removes it.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/time.c

@@ -38,7 +38,6 @@ int __weak rtc_mips_set_time(unsigned long sec)
 {
 	return 0;
 }
-EXPORT_SYMBOL(rtc_mips_set_time);
 
 int __weak rtc_mips_set_mmss(unsigned long nowtime)
 {