Modified conditional compile defines.

Simplified the #defines at the top of main.c by
using #if defined(RK1B2B) || defined(RK2B2B)
and #if defined(RK1NPC) || defined(RK2NPC) instead of
the #define b2b and #define npc so now there is only one define to set.

Just pick one.
//#define RK1B2B
//#define RK2B2B
//#define RK2NPC
Small fix for main function while(1) loop.
Additional changes to defines.

Getting ride of #define b2b and #define npc
in favor of #if define(RK1B2B) || define(RK2B2B).
Minor change to define RK1B2B as default