x86: ksysfs.c build fix

kbuild test robot report below error for randconfig:

arch/x86/kernel/ksysfs.c: In function 'get_setup_data_paddr':
arch/x86/kernel/ksysfs.c:81:3: error: implicit declaration of function 'ioremap_cache' [-Werror=implicit-function-declaration]
arch/x86/kernel/ksysfs.c:86:3: error: implicit declaration of function 'iounmap' [-Werror=implicit-function-declaration]

Fix it by including <asm/io.h> in ksysfs.c

Signed-off-by: Dave Young <[e-mail]>
Signed-off-by: Matt Fleming <[e-mail]>

arch/x86/kernel/ksysfs.c

···
 #include <linux/slab.h>
 #include <linux/mm.h>
 
+#include <asm/io.h>
 #include <asm/setup.h>
 
 static ssize_t version_show(struct kobject *kobj,