boards/nucleo-l152re: use its own openocd config file
boards/nucleo-l152re: use its own openocd config file

The nucleo-l152re is the only stm32l1x supported board with
two flash banks according to openocd config. Thus, adding
the right config file makes the whole flash available.

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