compat: generic compat get/settimeofday

Nothing arch specific in get/settimeofday.  The details of the timeval
conversion varied a little from arch to arch, but all with the same
results.

Also add an extern declaration for sys_tz to linux/time.h because externs
in .c files are fowned upon.  I'll kill the externs in various other files
in a sparate patch.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net> [ sparc bits ]
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/s390/kernel/syscalls.S

@@ -86,8 +86,8 @@ SYSCALL(sys_sethostname,sys_sethostname,sys32_sethostname_wrapper)
 SYSCALL(sys_setrlimit,sys_setrlimit,compat_sys_setrlimit_wrapper)	/* 75 */
 SYSCALL(sys_old_getrlimit,sys_getrlimit,compat_sys_old_getrlimit_wrapper)
 SYSCALL(sys_getrusage,sys_getrusage,compat_sys_getrusage_wrapper)
-SYSCALL(sys_gettimeofday,sys_gettimeofday,sys32_gettimeofday_wrapper)
-SYSCALL(sys_settimeofday,sys_settimeofday,sys32_settimeofday_wrapper)
+SYSCALL(sys_gettimeofday,sys_gettimeofday,compat_sys_gettimeofday_wrapper)
+SYSCALL(sys_settimeofday,sys_settimeofday,compat_sys_settimeofday_wrapper)
 SYSCALL(sys_getgroups16,sys_ni_syscall,sys32_getgroups16_wrapper)	/* 80 old getgroups16 syscall */
 SYSCALL(sys_setgroups16,sys_ni_syscall,sys32_setgroups16_wrapper)	/* old setgroups16 syscall */
 NI_SYSCALL							/* old select syscall */