ARM: EXYNOS: add coupled cpuidle support for Exynos3250

The following patch adds coupled cpuidle support for Exynos3250 to
an existing cpuidle-exynos driver.  As a result it enables AFTR mode
to be used by default on Exynos3250 without the need to hot unplug
CPU1 first.

The detailed changelog:
- use exynos_[get,set]_boot_addr() in cpuidle-exynos.c and then make
  cpu_boot_reg_base() static
- use exynos_core_restart() in exynos_cpu0_enter_aftr()
- add missing smp_rmb() to exynos_cpu0_enter_aftr() (to make the code
  in-sync with the platform SMP code)
- add call_firmware_op(cpu_boot, 1) to exynos_cpu0_enter_aftr()
- use dsb_sev() instead of IPI wakeup for Exynos3250 in
  exynos_cpu0_enter_aftr()
- add CPU0 vs CPU1 synchronization based on S5P_PMU_SPARE2 register
  for Exynos3250 to cpuidle-exynos.c
- add flush_cache_all() for CPU1/0 before powerdown/AFTR for
  Exynos3250 to exynos_wfi_finisher()/exynos_do_idle()

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>
diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
index b30562d..245f6de 100644
--- a/arch/arm/mach-exynos/firmware.c
+++ b/arch/arm/mach-exynos/firmware.c
@@ -49,6 +49,7 @@
 			     sysram_ns_base_addr + 0x24);
 		__raw_writel(EXYNOS_AFTR_MAGIC, sysram_ns_base_addr + 0x20);
 		if (soc_is_exynos3250()) {
+			flush_cache_all();
 			exynos_smc(SMC_CMD_SAVE, OP_TYPE_CORE,
 				   SMC_POWERSTATE_IDLE, 0);
 			exynos_smc(SMC_CMD_SHUTDOWN, OP_TYPE_CLUSTER,