flash/nor/stm32f1x: add can_load_options flag for GD32F1x0, F3x0 and E23x

flash/nor/stm32f1x: add can_load_options flag for GD32F1x0, F3x0 and E23x

According to GigaDevice user manuals the devices have OBRLD bit in FMC_CTL
register which is functionally compatible with OBL_LAUNCH @ FLASH_CR
of STM32 counterparts.

Change-Id: I84d231b38815fcb6452fd73b9153b269cce3b737
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/6759
Tested-by: jenkins
Reviewed-by: Andrzej Sierżęga <asier70@gmail.com>