ARM: EXYNOS: Fix build breakge with PM_SLEEP=n

Fix building of exynos_defconfig with disabled PM_SLEEP:
CONFIG_PM_SLEEP=n
CONFIG_PM_SLEEP_SMP=n
CONFIG_SUSPEND=n
by moving functions for power up/down of CPU and cluster to platsmp.c

The build error messages:
arch/arm/mach-exynos/built-in.o: In function `exynos_boot_secondary':
arch/arm/mach-exynos/platsmp.c:111: undefined reference to `exynos_cpu_power_state'
arch/arm/mach-exynos/platsmp.c:112: undefined reference to `exynos_cpu_power_up'
arch/arm/mach-exynos/platsmp.c:116: undefined reference to `exynos_cpu_power_state'
make: *** [vmlinux] Error 1

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com&gt;,>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>