[PATCH 1/4] powerpc/powernv: Add OPAL check token call

[Stewart Smith]

Michael Neuling <mikey at neuling.org> writes:
> Currently there is no way to generically check if an OPAL call exists or not
> from the host kernel.
>
> This adds an OPAL call opal_check_token() which tells you if the given token is
> present in OPAL or not.
>
> Signed-off-by: Michael Neuling <mikey at neuling.org>

(checked the firmware code)

Reviewed-by: Stewart Smith <stewart at linux.vnet.ibm.com>

(although should we be checking if the call returns OPAL_PARAMETER?
The opal call will return that if booting on firmware without
OPAL_CHECK_TOKEN.. which granted, is pretty old firmware that I don't
*think* we had leave the lab... or at least not to too many places)