ARM: kprobes: Move find_str_pc_offset into kprobes-common.c

Move str_pc_offset into kprobes-common.c as it will be needed by common
code later.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
diff --git a/arch/arm/kernel/kprobes.h b/arch/arm/kernel/kprobes.h
index 4de2f37..43f630d 100644
--- a/arch/arm/kernel/kprobes.h
+++ b/arch/arm/kernel/kprobes.h
@@ -36,6 +36,8 @@
 
 extern kprobe_check_cc * const kprobe_condition_checks[16];
 
+extern int str_pc_offset;
+
 /*
  * Test if load/store instructions writeback the address register.
  * if P (bit 24) == 0 or W (bit 21) == 1