cpu/esp32: additional _ removed from __uart_*
cpu/esp32: additional _ removed from __uart_*

An additional _ for static symbols has been added by mistake and should be removed. This will make future merging with the reimplementation of ESP8266 easier.
rfuentess/RIOT,aeneby/RIOT,kYc0o/RIOT,OTAkeys/RIOT,rfuentess/RIOT,lazytech-org/RIOT,josephnoir/RIOT,mtausig/RIOT,lazytech-org/RIOT,RIOT-OS/RIOT,ant9000/RIOT,ant9000/RIOT,mtausig/RIOT,yogo1212/RIOT,aeneby/RIOT,yogo1212/RIOT,basilfx/RIOT,mfrey/RIOT,mtausig/RIOT,smlng/RIOT,josephnoir/RIOT,aeneby/RIOT,jasonatran/RIOT,basilfx/RIOT,x3ro/RIOT,aeneby/RIOT,cladmi/RIOT,basilfx/RIOT,kaspar030/RIOT,OTAkeys/RIOT,cladmi/RIOT,cladmi/RIOT,RIOT-OS/RIOT,mtausig/RIOT,kaspar030/RIOT,kaspar030/RIOT,kaspar030/RIOT,kaspar030/RIOT,smlng/RIOT,rfuentess/RIOT,rfuentess/RIOT,jasonatran/RIOT,josephnoir/RIOT,toonst/RIOT,josephnoir/RIOT,mfrey/RIOT,x3ro/RIOT,authmillenon/RIOT,OlegHahm/RIOT,smlng/RIOT,OTAkeys/RIOT,miri64/RIOT,OlegHahm/RIOT,miri64/RIOT,basilfx/RIOT,OlegHahm/RIOT,kYc0o/RIOT,cladmi/RIOT,jasonatran/RIOT,mfrey/RIOT,rfuentess/RIOT,x3ro/RIOT,x3ro/RIOT,jasonatran/RIOT,ant9000/RIOT,yogo1212/RIOT,smlng/RIOT,ant9000/RIOT,RIOT-OS/RIOT,mtausig/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,x3ro/RIOT,lazytech-org/RIOT,jasonatran/RIOT,aeneby/RIOT,miri64/RIOT,lazytech-org/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,yogo1212/RIOT,toonst/RIOT,mfrey/RIOT,OTAkeys/RIOT,OTAkeys/RIOT,smlng/RIOT,toonst/RIOT,RIOT-OS/RIOT,ant9000/RIOT,cladmi/RIOT,basilfx/RIOT,josephnoir/RIOT,miri64/RIOT,yogo1212/RIOT,miri64/RIOT,lazytech-org/RIOT,authmillenon/RIOT,toonst/RIOT,toonst/RIOT,mfrey/RIOT,kYc0o/RIOT,authmillenon/RIOT,kYc0o/RIOT,authmillenon/RIOT,yogo1212/RIOT,authmillenon/RIOT,authmillenon/RIOT