This changes the cpu_idle loop for 44x platforms to utilize the Wait Enable
feature of the CPU. This helps virtulization solutions know when the guest
Linux kernel is in an idle state.
A command line option called "idle" is also added to allow people to change
the idle loop back to the original variation. This is done by setting
"idle=spin" on the kernel command line.
Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>