flash/nor/stm32f1x: Ability to change user option bytes.
Adds ability to change the user data in STM32F1x/STM32F3x MCU's option byte.
Since OpenOCD prints the content of user data in option byte registers, it
is seems logical to also provide a way how to change this data.
Change-Id: Ie6cb756b4f11b5c6dabd34bc89434a358eb758ff
Signed-off-by: Jan Vojtech <honza.vojtech@gmail.com>
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4663
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>