x86: Show the interrupt pointer with 'irqinfo'

It is useful for this command to show the address of the interrupt table.
Add support for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/i386/interrupt.c b/arch/x86/cpu/i386/interrupt.c
index c0c4bc9..d85f84b 100644
--- a/arch/x86/cpu/i386/interrupt.c
+++ b/arch/x86/cpu/i386/interrupt.c
@@ -180,16 +180,11 @@
 	u16	base_high;
 } __packed;
 
-struct desc_ptr {
-	unsigned short size;
-	unsigned long address;
-} __packed;
-
 struct idt_entry idt[256] __aligned(16);
 
-struct desc_ptr idt_ptr;
+struct idt_ptr idt_ptr;
 
-static inline void load_idt(const struct desc_ptr *dtr)
+static inline void load_idt(const struct idt_ptr *dtr)
 {
 	asm volatile("cs lidt %0" : : "m" (*dtr));
 }
@@ -232,6 +227,11 @@
 	return 0;
 }
 
+void interrupt_read_idt(struct idt_ptr *ptr)
+{
+	asm volatile("sidt %0" : : "m" (*ptr));
+}
+
 void *x86_get_idt(void)
 {
 	return &idt_ptr;