kinetis: Add support for low-end MCG without PLL
kinetis: Add support for low-end MCG without PLL

Found in Kinetis L series, among others

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