ARM: EXYNOS4: Remove compiler warning on exynos4_pwm4_resume

Remove compiler warning when no CONFIG_PM

arch/arm/mach-exynos4/time.c:209:
        warning: 'exynos4_pwm4_resume' defined but not used

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>