ARM: 6472/1: vexpress ct-ca9x4: only set twd_base if local timers are being used

In commit bde28b84, I made the assumption that CONFIG_SMP is always set
for the quad-core ct-ca9x4 platform. As it turns out, people who aren't
using the SMP goodness are confronted with a build failure.

This patch fixes this issue by ensure that twd_base is only set if
local timers are being used (and therefore SMP support is configured).
Reported-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-vexpress/ct-ca9x4.c

@@ -54,7 +54,9 @@ static struct map_desc ct_ca9x4_io_desc[] __initdata = {
 
 static void __init ct_ca9x4_map_io(void)
 {
+#ifdef CONFIG_LOCAL_TIMERS
 	twd_base = MMIO_P2V(A9_MPCORE_TWD);
+#endif
 	v2m_map_io(ct_ca9x4_io_desc, ARRAY_SIZE(ct_ca9x4_io_desc));
 }