cpu/lpc2387: PM: enable SLEEP & POWERDOWN mode
cpu/lpc2387: PM: enable SLEEP & POWERDOWN mode

We have to re-init PLL (and Flash) after wake from those modes.

basilfx/RIOT,authmillenon/RIOT,OlegHahm/RIOT,jasonatran/RIOT,basilfx/RIOT,basilfx/RIOT,kYc0o/RIOT,jasonatran/RIOT,OTAkeys/RIOT,ant9000/RIOT,kYc0o/RIOT,miri64/RIOT,authmillenon/RIOT,authmillenon/RIOT,miri64/RIOT,OTAkeys/RIOT,jasonatran/RIOT,kYc0o/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,ant9000/RIOT,OlegHahm/RIOT,basilfx/RIOT,miri64/RIOT,OTAkeys/RIOT,ant9000/RIOT,jasonatran/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,jasonatran/RIOT,kaspar030/RIOT,ant9000/RIOT,miri64/RIOT,kaspar030/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,kYc0o/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,kaspar030/RIOT,ant9000/RIOT,basilfx/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,miri64/RIOT,authmillenon/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,authmillenon/RIOT