arch/x86: replace strict_strto calls

Replace obsolete strict_strto calls with appropriate kstrto calls

Signed-off-by: Daniel Walter <dwalter@google.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>