[Skiboot] [PATCHv2 1/6] SLW: Add support for p9_stop_api

[Gautham R Shenoy]

On Wed, Jul 05, 2017 at 04:08:36PM +0530, Akshay Adiga wrote:
> p9_stop_api's are used to SPR state on a core wakeup form a deeper state.
> p9_stop_api uses  low level platform formware and self-restore microcode
> to restore the sprs to requested values.
> 
> Code is taken from :
> https://github.com/open-power/hostboot/tree/master/src/import/chips/p9/procedures/utils/stopreg
> This code is still under development.
> 
> Signed-off-by: Akshay Adiga <akshay.adiga at linux.vnet.ibm.com>

Tested-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>