x86: cpu: Skip init code when chain loading

When U-Boot is not the first-stage bootloader the interrupt and cache init
must be skipped, as well as init for various peripherals. Update the code
to add checks for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index cec04b4..8526e85 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -239,8 +239,10 @@
 	struct udevice *dev;
 	int ret;
 
-	if (!ll_boot_init())
+	if (!ll_boot_init()) {
+		uclass_first_device(UCLASS_PCI, &dev);
 		return 0;
+	}
 
 	ret = x86_init_cpus();
 	if (ret)
diff --git a/arch/x86/cpu/i386/interrupt.c b/arch/x86/cpu/i386/interrupt.c
index 4c7e9ea..e67a116 100644
--- a/arch/x86/cpu/i386/interrupt.c
+++ b/arch/x86/cpu/i386/interrupt.c
@@ -264,6 +264,9 @@
 	struct udevice *dev;
 	int ret;
 
+	if (!ll_boot_init())
+		return 0;
+
 	/* Try to set up the interrupt router, but don't require one */
 	ret = irq_first_device_type(X86_IRQT_BASE, &dev);
 	if (ret && ret != -ENODEV)
@@ -295,8 +298,7 @@
 	 * TODO(sjg@chromium.org): But we don't handle these correctly when
 	 * booted from EFI.
 	 */
-	if (ll_boot_init())
-		enable_interrupts();
+	enable_interrupts();
 #endif
 
 	return 0;
diff --git a/arch/x86/lib/init_helpers.c b/arch/x86/lib/init_helpers.c
index 5bb55e2..d906b52 100644
--- a/arch/x86/lib/init_helpers.c
+++ b/arch/x86/lib/init_helpers.c
@@ -30,6 +30,9 @@
 			return ret;
 	}
 
+	if (!ll_boot_init())
+		return 0;
+
 	/* Initialise the CPU cache(s) */
 	return init_cache();
 }