x86: use explicit copy in vdso_gettimeofday()

Jeremy's gcc 3.4 seems to be unable to inline a 8 byte memcpy.  But the
vdso doesn't support external references.  Copy the structure members
of struct timezone explicitely instead.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>