add_auto_stkpnt

Add automatic SP register change point
     func_ea  - function start
     ea       - linear address where SP changes
                usually this is the end of the instruction which
                modifies the stack pointer (cmd.ea+cmd.size)
     delta    - difference between old and new values of SP
returns: 1-ok, 0-failed

success add_auto_stkpnt(func_ea, ea, sval_t delta);