ARM: EXYNOS: Do not calculate boot address twice

Commit b3205dea ("ARM: EXYNOS: Map SYSRAM through generic DT
bindings") introduced local variable boot_reg where boot address from
cpu_boot_reg() call is stored. Re-use it instead calling cpu_boot_reg()
again.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Sachin Kamat <sachin.kamat@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/platsmp.c

@@ -224,7 +224,7 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
 				ret = PTR_ERR(boot_reg);
 				goto fail;
 			}
-			__raw_writel(boot_addr, cpu_boot_reg(core_id));
+			__raw_writel(boot_addr, boot_reg);
 		}
 
 		call_firmware_op(cpu_boot, core_id);
@@ -313,7 +313,7 @@ static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
 
 			if (IS_ERR(boot_reg))
 				break;
-			__raw_writel(boot_addr, cpu_boot_reg(core_id));
+			__raw_writel(boot_addr, boot_reg);
 		}
 	}
 }