support OpenOCD 0.6.1 --enable-stlink

Hi
I changed OpenOCD version 0.6.0 to 0.6.1.
It supports --enable-stlink.
I test by using linaro arm-none-eabi-gdb and openocd on a STM32F4-Discovery board.
In the case of using with a gdb 7.2 or upper, it needed to patch OpenOCD's FP register code,
so I modified it.