parisc: Export __cmpxchg_u64 unconditionally

__cmpxchg_u64 is built and used outside CONFIG_64BIT and thus needs to
be exported. This fixes the following build error seen when building
parisc:allmodconfig.

ERROR: "__cmpxchg_u64" [drivers/net/ethernet/intel/i40e/i40e.ko] undefined!
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/parisc_ksyms.c

@@ -35,12 +35,12 @@ EXPORT_SYMBOL(memset);
 EXPORT_SYMBOL(__xchg8);
 EXPORT_SYMBOL(__xchg32);
 EXPORT_SYMBOL(__cmpxchg_u32);
+EXPORT_SYMBOL(__cmpxchg_u64);
 #ifdef CONFIG_SMP
 EXPORT_SYMBOL(__atomic_hash);
 #endif
 #ifdef CONFIG_64BIT
 EXPORT_SYMBOL(__xchg64);
-EXPORT_SYMBOL(__cmpxchg_u64);
 #endif
 
 #include <linux/uaccess.h>