* cpu.c: Implemented _CPU_Context_Initialize as a C function instead
of a macro. It works with limited functionality. Implemented
_CPU_Thread_Idle_body to use sleep instruction.
* Makefile.am: Changed cpu_asm.c -> cpu_asm.S
* cpu_asm.S: renamed from cpu_asm.c and implemented functions is asm
* rtems/asm.h: Appended "macros.inc" to the end of "asm.h"
* rtems/score/cpu.h:
+ Included "avr/io.h".
+ Added use 16 bit object definition.
+ Modified Context_Control struct to relect the registers
that need to be saved.
+ Implemented _CPU_ISR_Disable, _CPU_ISR_Enable, and _CPU_ISR_Flash.
Added function definitions for _CPU_Context_Initialize and
_CPU_Push.