Remove "hardware" from comments of "target_insert_breakpoint"

Remove "hardware" from comments of "target_insert_breakpoint"

This function is for simple breakpoint.  So I post a patch to remove "hardware".

Thanks,
Hui

2014-03-10  Hui Zhu  <hui@codesourcery.com>

	* target.h (target_insert_breakpoint): Remove "hardware" from its
	comments.