makefile/tools/esptool: use dio instead of qout or qio flash mode
makefile/tools/esptool: use dio instead of qout or qio flash mode

If Quad SPI modes qout or qio are set by variable FLASH_MODE, esptool.py has to be called with parameter `--flash_mode dio` so that the first stage bootloader is always using Dual SPI mode.
RIOT-OS/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,ant9000/RIOT,kaspar030/RIOT,kaspar030/RIOT,ant9000/RIOT,kYc0o/RIOT,ant9000/RIOT,jasonatran/RIOT,kYc0o/RIOT,kaspar030/RIOT,miri64/RIOT,kYc0o/RIOT,ant9000/RIOT,jasonatran/RIOT,kaspar030/RIOT,miri64/RIOT,miri64/RIOT,RIOT-OS/RIOT,ant9000/RIOT,miri64/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,miri64/RIOT,kaspar030/RIOT,kYc0o/RIOT,jasonatran/RIOT