ARM: EXYNOS: add exynos_get_boot_addr() helper

Add get_cpu_boot_addr() firmware operation and then
exynos_get_boot_addr() helper.

This is a preparation for adding coupled cpuidle support
for Exynos3250 SoC.

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>
diff --git a/arch/arm/include/asm/firmware.h b/arch/arm/include/asm/firmware.h
index 89aefe1..34c1d96 100644
--- a/arch/arm/include/asm/firmware.h
+++ b/arch/arm/include/asm/firmware.h
@@ -34,6 +34,10 @@
 	 */
 	int (*set_cpu_boot_addr)(int cpu, unsigned long boot_addr);
 	/*
+	 * Gets boot address of specified physical CPU
+	 */
+	int (*get_cpu_boot_addr)(int cpu, unsigned long *boot_addr);
+	/*
 	 * Boots specified physical CPU
 	 */
 	int (*cpu_boot)(int cpu);