msm: timer: Fix SMP build error

Fix build breakage on SMP=y builds due to 0f7b332f (ARM:
consolidate SMP cross call implementation, 2011-04-03)

arch/arm/mach-msm/timer.c: In function 'local_timer_setup':
arch/arm/mach-msm/timer.c:295: error: implicit declaration of
function 'gic_enable_ppi'
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>

arch/arm/mach-msm/timer.c

@@ -23,6 +23,8 @@
 #include <linux/io.h>
 
 #include <asm/mach/time.h>
+#include <asm/hardware/gic.h>
+
 #include <mach/msm_iomap.h>
 #include <mach/cpu.h>