more 2 MHz (VLPR) fixes 

removed SMC_PMCTRL_STOPM(2) from VLPR routine, not needed since we just want to go into VLPR not stop mode.

moved SMC_PMPROT to be visible to all F_CPU, this allows for sleep modes at any F_CPU. 

changed deleyMicroseconds because of bug with 1 microsecond delay @ 2MHz is 0.