cpu/samd21: fix NVM wait states
cpu/samd21: fix NVM wait states

Signed-off-by: dylad <d56dfe611c7cd6204525c7c9b6afc5e84aed0f5d@mesotic.com>

ant9000/RIOT,ks156/RIOT,OTAkeys/RIOT,gebart/RIOT,syin2/RIOT,rfuentess/RIOT,gautric/RIOT,cladmi/RIOT,biboc/RIOT,adrianghc/RIOT,roberthartung/RIOT,BytesGalore/RIOT,avmelnikoff/RIOT,BytesGalore/RIOT,cladmi/RIOT,smlng/RIOT,plushvoxel/RIOT,RIOT-OS/RIOT,ant9000/RIOT,yogo1212/RIOT,BytesGalore/RIOT,Hyungsin/RIOT-OS,aeneby/RIOT,plushvoxel/RIOT,OlegHahm/RIOT,hamilton-mote/RIOT-OS,plushvoxel/RIOT,gautric/RIOT,thomaseichinger/RIOT,adrianghc/RIOT,basilfx/RIOT,kbumsik/RIOT,beurdouche/RIOT,kYc0o/RIOT,dkm/RIOT,avmelnikoff/RIOT,aeneby/RIOT,kerneltask/RIOT,ks156/RIOT,smlng/RIOT,beurdouche/RIOT,rfuentess/RIOT,gautric/RIOT,cladmi/RIOT,hamilton-mote/RIOT-OS,adjih/RIOT,neumodisch/RIOT,Hyungsin/RIOT-OS,LudwigKnuepfer/RIOT,A-Paul/RIOT,adjih/RIOT,kerneltask/RIOT,lazytech-org/RIOT,Ell-i/RIOT,smlng/RIOT,x3ro/RIOT,lazytech-org/RIOT,dkm/RIOT,yogo1212/RIOT,LudwigOrtmann/RIOT,jasonatran/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,immesys/RiSyn,roberthartung/RIOT,authmillenon/RIOT,dailab/RIOT,Ell-i/RIOT,kaleb-himes/RIOT,thomaseichinger/RIOT,mfrey/RIOT,immesys/RiSyn,neumodisch/RIOT,A-Paul/RIOT,BytesGalore/RIOT,RIOT-OS/RIOT,syin2/RIOT,BytesGalore/RIOT,kbumsik/RIOT,dailab/RIOT,biboc/RIOT,Josar/RIOT,ant9000/RIOT,A-Paul/RIOT,authmillenon/RIOT,beurdouche/RIOT,mfrey/RIOT,kYc0o/RIOT,dailab/RIOT,toonst/RIOT,authmillenon/RIOT,immesys/RiSyn,josephnoir/RIOT,LudwigOrtmann/RIOT,neumodisch/RIOT,kbumsik/RIOT,kerneltask/RIOT,mfrey/RIOT,aeneby/RIOT,miri64/RIOT,A-Paul/RIOT,Josar/RIOT,jfischer-phytec-iot/RIOT,thomaseichinger/RIOT,kYc0o/RIOT,gautric/RIOT,miri64/RIOT,mtausig/RIOT,avmelnikoff/RIOT,cladmi/RIOT,RIOT-OS/RIOT,toonst/RIOT,beurdouche/RIOT,gebart/RIOT,x3ro/RIOT,OTAkeys/RIOT,avmelnikoff/RIOT,dailab/RIOT,x3ro/RIOT,josephnoir/RIOT,jfischer-phytec-iot/RIOT,OlegHahm/RIOT,adrianghc/RIOT,LudwigKnuepfer/RIOT,authmillenon/RIOT,LudwigOrtmann/RIOT,OTAkeys/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,authmillenon/RIOT,ks156/RIOT,kaspar030/RIOT,hamilton-mote/RIOT-OS,toonst/RIOT,miri64/RIOT,adjih/RIOT,Hyungsin/RIOT-OS,RIOT-OS/RIOT,A-Paul/RIOT,neumodisch/RIOT,LudwigOrtmann/RIOT,LudwigOrtmann/RIOT,OlegHahm/RIOT,lazytech-org/RIOT,jasonatran/RIOT,avmelnikoff/RIOT,adrianghc/RIOT,dkm/RIOT,adjih/RIOT,ant9000/RIOT,biboc/RIOT,mtausig/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,OTAkeys/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,neiljay/RIOT,kaspar030/RIOT,gebart/RIOT,Ell-i/RIOT,plushvoxel/RIOT,thomaseichinger/RIOT,OlegHahm/RIOT,neiljay/RIOT,immesys/RiSyn,mfrey/RIOT,kbumsik/RIOT,LudwigOrtmann/RIOT,hamilton-mote/RIOT-OS,aeneby/RIOT,josephnoir/RIOT,kaleb-himes/RIOT,smlng/RIOT,gautric/RIOT,josephnoir/RIOT,plushvoxel/RIOT,immesys/RiSyn,LudwigKnuepfer/RIOT,dkm/RIOT,josephnoir/RIOT,x3ro/RIOT,biboc/RIOT,adjih/RIOT,neiljay/RIOT,basilfx/RIOT,cladmi/RIOT,Hyungsin/RIOT-OS,miri64/RIOT,immesys/RiSyn,jasonatran/RIOT,lazytech-org/RIOT,jfischer-phytec-iot/RIOT,RIOT-OS/RIOT,miri64/RIOT,basilfx/RIOT,neumodisch/RIOT,mtausig/RIOT,roberthartung/RIOT,ks156/RIOT,OlegHahm/RIOT,hamilton-mote/RIOT-OS,ks156/RIOT,syin2/RIOT,jfischer-phytec-iot/RIOT,neumodisch/RIOT,yogo1212/RIOT,biboc/RIOT,kbumsik/RIOT,rfuentess/RIOT,mtausig/RIOT,toonst/RIOT,roberthartung/RIOT,roberthartung/RIOT,yogo1212/RIOT,toonst/RIOT,lazytech-org/RIOT,kaleb-himes/RIOT,smlng/RIOT,jasonatran/RIOT,kaspar030/RIOT,rfuentess/RIOT,kaspar030/RIOT,LudwigKnuepfer/RIOT,kYc0o/RIOT,ant9000/RIOT,LudwigKnuepfer/RIOT,Josar/RIOT,yogo1212/RIOT,dailab/RIOT,Ell-i/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,kaspar030/RIOT,kaleb-himes/RIOT,kYc0o/RIOT,gebart/RIOT,basilfx/RIOT,gebart/RIOT,Josar/RIOT,neiljay/RIOT,mtausig/RIOT,neiljay/RIOT,jasonatran/RIOT,aeneby/RIOT,rfuentess/RIOT,Josar/RIOT,x3ro/RIOT,thomaseichinger/RIOT,Ell-i/RIOT,beurdouche/RIOT,mfrey/RIOT,OTAkeys/RIOT,adrianghc/RIOT,authmillenon/RIOT,yogo1212/RIOT,syin2/RIOT,Hyungsin/RIOT-OS,jfischer-phytec-iot/RIOT,syin2/RIOT,kaleb-himes/RIOT,kerneltask/RIOT,dkm/RIOT,basilfx/RIOT,kerneltask/RIOT