ARM: EXYNOS: Fix build error without CONFIG_LOCAL_TIMERS

arch/arm/mach-exynos/mct.c: In function 'exynos4_timer_resources':
arch/arm/mach-exynos/mct.c:450: error: 'exynos4_mct_tick_isr' undeclared (first use in this function)
arch/arm/mach-exynos/mct.c:450: error: (Each undeclared identifier is reported only once
arch/arm/mach-exynos/mct.c:450: error: for each function it appears in.)
make[1]: *** [arch/arm/mach-exynos/mct.o] Error 1

Reported-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>