cpu/esp32: fix periph_flash timing problems
cpu/esp32: fix periph_flash timing problems

While deleting multiple sectors in flash, interrupts were disabled over the whole time. Thus, deleting the entire flash led to the triggering of the watchdog timer and thus to a restart. Therefore, the interrupts and the cache are disabled only for the time of deleting a single sector. The same problem occurred for read and write large data sets.
yogo1212/RIOT,OTAkeys/RIOT,basilfx/RIOT,kaspar030/RIOT,toonst/RIOT,RIOT-OS/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,josephnoir/RIOT,kYc0o/RIOT,toonst/RIOT,josephnoir/RIOT,yogo1212/RIOT,mtausig/RIOT,aeneby/RIOT,ant9000/RIOT,aeneby/RIOT,authmillenon/RIOT,kaspar030/RIOT,x3ro/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,josephnoir/RIOT,kYc0o/RIOT,smlng/RIOT,aeneby/RIOT,basilfx/RIOT,kaspar030/RIOT,OTAkeys/RIOT,kYc0o/RIOT,ant9000/RIOT,jasonatran/RIOT,kYc0o/RIOT,OlegHahm/RIOT,miri64/RIOT,x3ro/RIOT,OTAkeys/RIOT,kaspar030/RIOT,mtausig/RIOT,mtausig/RIOT,toonst/RIOT,OTAkeys/RIOT,basilfx/RIOT,aeneby/RIOT,RIOT-OS/RIOT,josephnoir/RIOT,OlegHahm/RIOT,toonst/RIOT,authmillenon/RIOT,miri64/RIOT,authmillenon/RIOT,jasonatran/RIOT,ant9000/RIOT,authmillenon/RIOT,x3ro/RIOT,ant9000/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,jasonatran/RIOT,basilfx/RIOT,mtausig/RIOT,x3ro/RIOT,smlng/RIOT,yogo1212/RIOT,jasonatran/RIOT,x3ro/RIOT,authmillenon/RIOT,aeneby/RIOT,miri64/RIOT,kaspar030/RIOT,OlegHahm/RIOT,smlng/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,toonst/RIOT,mtausig/RIOT,kYc0o/RIOT,smlng/RIOT,miri64/RIOT,basilfx/RIOT,josephnoir/RIOT,ant9000/RIOT,yogo1212/RIOT,smlng/RIOT,miri64/RIOT,authmillenon/RIOT