when LPC is disabled ,linux_inb should not be accessed by kbd

Signed-off-by: niupj <niupengju@loongson.cn>

Targets/Bonito3a4000_7a/conf/Bonito.3a4000_7a

@@ -303,3 +303,4 @@ select tftpd
 # SCSI RAID disk drive support
 select scsi_sd
 select raw_ether
+option LS7A_LPC_KBD_DISABLE

pmon/dev/kbd.h

@@ -49,6 +49,11 @@ extern unsigned int superio_base;
 #define kbd_read_status() 	inb(KBD_STATUS_REG)
 #define kbd_write_output(val) 	outb(KBD_DATA_REG,val)
 #define kbd_write_command(val) 	outb(KBD_CNTL_REG, val)
+#elif (defined(LS7A_LPC_KBD_DISABLE))
+#define kbd_read_input()	0
+#define kbd_read_status()	0
+#define kbd_write_output(val)	0
+#define kbd_write_command(val)	0
 
 #else
 #define kbd_read_input()	linux_inb(KBD_DATA_REG)