Moved entire memory to higher memory location to prevent overlap when kernel is loaded into memory.

* Changed base and entry points for haiku_loader_nbsd.ub.
* Changed base address for SDRAM and framebuffer.
* Use variable defined in BoardSetup instead of hardcoding in Jamfile.
Disable frame buffer for now since it's not essential. Fix involves correcting fault when writing to CM_CLKSEL_DSS.