x86/kprobes: Split out optprobe related code to kprobes-opt.c

Split out optprobe related code to arch/x86/kernel/kprobes-opt.c
for maintenanceability.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: systemtap@sourceware.org
Cc: anderson@redhat.com
Link: http://lkml.kernel.org/r/20120305133222.5982.54794.stgit@localhost.localdomain


[ Tidied up the code a tiny bit ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>