unittests/littlefs: fix unittests
unittests/littlefs: fix unittests

Dummy RAM mtd was too small to run unit tests correctly.
Added some sectors and reduced page size.

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