ARM: EXYNOS: add secondary CPU boot base location for EXYNOS5420

The location at which the boot address is specified for secondary
CPUs of EXYNOS5420 is SYSRAM base + 4. Update the cpu_boot_reg
function accordingly.
Signed-off-by: NChander Kashyap <chander.kashyap@linaro.org>
Reviewed-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/platsmp.c

@@ -50,6 +50,8 @@ static inline void __iomem *cpu_boot_reg(int cpu)
 	boot_reg = cpu_boot_reg_base();
 	if (soc_is_exynos4412())
 		boot_reg += 4*cpu;
+	else if (soc_is_exynos5420())
+		boot_reg += 4;
 	return boot_reg;
 }