x86: move get_segment_eip() to step.c

get_segment_eip has similarities to convert_rip_to_linear(),
and is used in a similar context.  Move get_segment_eip to
step.c to allow easier consolidation.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/ptrace.h b/include/asm-x86/ptrace.h
index 61946fe..cc44566 100644
--- a/include/asm-x86/ptrace.h
+++ b/include/asm-x86/ptrace.h
@@ -184,6 +184,8 @@
 
 #ifdef __KERNEL__
 
+unsigned long get_segment_eip(struct pt_regs *regs, unsigned long *eip_limit);
+
 /*
  * These are defined as per linux/ptrace.h, which see.
  */