x86/irq: Correct comment about i8259 initialization

0x30-0x3f have been used for ISA interrupts on i386 as well
since 5 years ago, but old comments about i8259 initialization
were still referring to the old i386 usage of this port range.

Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Cc: yinghai@kernel.org
Cc: pavel@suse.cz
Link: http://lkml.kernel.org/r/1378257924-29446-1-git-send-email-ycnian@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/i8259.c

@@ -312,8 +312,7 @@ static void init_8259A(int auto_eoi)
 	 */
 	outb_pic(0x11, PIC_MASTER_CMD);	/* ICW1: select 8259A-1 init */
 
-	/* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64,
-	   to 0x20-0x27 on i386 */
+	/* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 */
 	outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
 
 	/* 8259A-1 (the master) has a slave on IR2 */