cpu/esp32: fixes printf and puts
cpu/esp32: fixes printf and puts

printf and puts used ets_printf before. Unfortunately, ets_printf adds an additional \r for each \n which is not consistent with other RIOT platforms. As a result some automatic tests failed. Therefore, both functions write now character-wise directly to the UART interface.
authmillenon/RIOT,rfuentess/RIOT,kYc0o/RIOT,OTAkeys/RIOT,x3ro/RIOT,rfuentess/RIOT,x3ro/RIOT,josephnoir/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,basilfx/RIOT,kYc0o/RIOT,OlegHahm/RIOT,yogo1212/RIOT,rfuentess/RIOT,cladmi/RIOT,OlegHahm/RIOT,aeneby/RIOT,kaspar030/RIOT,OTAkeys/RIOT,smlng/RIOT,cladmi/RIOT,ant9000/RIOT,mtausig/RIOT,OTAkeys/RIOT,mtausig/RIOT,basilfx/RIOT,smlng/RIOT,kaspar030/RIOT,OTAkeys/RIOT,toonst/RIOT,mtausig/RIOT,yogo1212/RIOT,toonst/RIOT,x3ro/RIOT,josephnoir/RIOT,kYc0o/RIOT,mtausig/RIOT,cladmi/RIOT,kaspar030/RIOT,smlng/RIOT,jasonatran/RIOT,authmillenon/RIOT,miri64/RIOT,x3ro/RIOT,ant9000/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,yogo1212/RIOT,kYc0o/RIOT,aeneby/RIOT,OlegHahm/RIOT,aeneby/RIOT,toonst/RIOT,cladmi/RIOT,jasonatran/RIOT,cladmi/RIOT,authmillenon/RIOT,smlng/RIOT,RIOT-OS/RIOT,toonst/RIOT,josephnoir/RIOT,basilfx/RIOT,authmillenon/RIOT,rfuentess/RIOT,ant9000/RIOT,kaspar030/RIOT,mtausig/RIOT,smlng/RIOT,yogo1212/RIOT,miri64/RIOT,OlegHahm/RIOT,x3ro/RIOT,authmillenon/RIOT,aeneby/RIOT,toonst/RIOT,miri64/RIOT,kYc0o/RIOT,miri64/RIOT,aeneby/RIOT,yogo1212/RIOT,josephnoir/RIOT,ant9000/RIOT,basilfx/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,miri64/RIOT,yogo1212/RIOT,OTAkeys/RIOT,rfuentess/RIOT,RIOT-OS/RIOT,josephnoir/RIOT,basilfx/RIOT,ant9000/RIOT,jasonatran/RIOT,jasonatran/RIOT,jasonatran/RIOT