mtd_spi_nor: make thread safe
mtd_spi_nor: make thread safe

cladmi/RIOT,ant9000/RIOT,kbumsik/RIOT,gebart/RIOT,cladmi/RIOT,x3ro/RIOT,biboc/RIOT,rfuentess/RIOT,miri64/RIOT,RIOT-OS/RIOT,smlng/RIOT,neiljay/RIOT,biboc/RIOT,mtausig/RIOT,toonst/RIOT,gebart/RIOT,rfuentess/RIOT,OTAkeys/RIOT,kaspar030/RIOT,mfrey/RIOT,miri64/RIOT,miri64/RIOT,x3ro/RIOT,kYc0o/RIOT,rfuentess/RIOT,gebart/RIOT,cladmi/RIOT,toonst/RIOT,aeneby/RIOT,OlegHahm/RIOT,authmillenon/RIOT,A-Paul/RIOT,yogo1212/RIOT,BytesGalore/RIOT,OlegHahm/RIOT,mtausig/RIOT,lazytech-org/RIOT,rfuentess/RIOT,toonst/RIOT,jasonatran/RIOT,yogo1212/RIOT,aeneby/RIOT,mfrey/RIOT,miri64/RIOT,avmelnikoff/RIOT,A-Paul/RIOT,BytesGalore/RIOT,kaspar030/RIOT,gebart/RIOT,smlng/RIOT,avmelnikoff/RIOT,mtausig/RIOT,jasonatran/RIOT,basilfx/RIOT,RIOT-OS/RIOT,basilfx/RIOT,yogo1212/RIOT,lazytech-org/RIOT,OlegHahm/RIOT,kbumsik/RIOT,authmillenon/RIOT,gebart/RIOT,biboc/RIOT,aeneby/RIOT,josephnoir/RIOT,lazytech-org/RIOT,kbumsik/RIOT,BytesGalore/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,OlegHahm/RIOT,josephnoir/RIOT,yogo1212/RIOT,biboc/RIOT,A-Paul/RIOT,josephnoir/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,ant9000/RIOT,lazytech-org/RIOT,yogo1212/RIOT,avmelnikoff/RIOT,cladmi/RIOT,authmillenon/RIOT,kbumsik/RIOT,kaspar030/RIOT,neiljay/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,OTAkeys/RIOT,A-Paul/RIOT,toonst/RIOT,x3ro/RIOT,ant9000/RIOT,mfrey/RIOT,avmelnikoff/RIOT,basilfx/RIOT,aeneby/RIOT,kbumsik/RIOT,neiljay/RIOT,OTAkeys/RIOT,smlng/RIOT,mtausig/RIOT,rfuentess/RIOT,miri64/RIOT,BytesGalore/RIOT,OTAkeys/RIOT,kYc0o/RIOT,kaspar030/RIOT,neiljay/RIOT,cladmi/RIOT,jasonatran/RIOT,BytesGalore/RIOT,biboc/RIOT,x3ro/RIOT,avmelnikoff/RIOT,josephnoir/RIOT,ant9000/RIOT,A-Paul/RIOT,mfrey/RIOT,neiljay/RIOT,toonst/RIOT,ant9000/RIOT,kYc0o/RIOT,basilfx/RIOT,mfrey/RIOT,jasonatran/RIOT,OlegHahm/RIOT,kYc0o/RIOT,mtausig/RIOT,yogo1212/RIOT,lazytech-org/RIOT,x3ro/RIOT,authmillenon/RIOT,josephnoir/RIOT,OTAkeys/RIOT,smlng/RIOT,kYc0o/RIOT,aeneby/RIOT,smlng/RIOT,basilfx/RIOT