powerpc/85xx: add hardware automatically enter altivec idle state
powerpc/85xx: add hardware automatically enter altivec idle state

Each core's AltiVec unit may be placed into a power savings mode
by turning off power to the unit. Core hardware will automatically
power down the AltiVec unit after no AltiVec instructions have
executed in N cycles. The AltiVec power-control is triggered by hardware.

Signed-off-by: Wang Dongsheng <5960aaaba185a50e91c7ab03e3fa96b745a59480@freescale.com>
Signed-off-by: Scott Wood <b77916c2feab81a70245e7b5671f4f02730ebf64@freescale.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs