powerpc/powernv: Add support for powercap framework

Adds a generic powercap framework to change the system powercap
inband through OPAL-OCC command/response interface.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/opal.c

@@ -850,6 +850,9 @@ static int __init opal_init(void)
 	/* Initialise OPAL kmsg dumper for flushing console on panic */
 	opal_kmsg_init();
 
+	/* Initialise OPAL powercap interface */
+	opal_powercap_init();
+
 	return 0;
 }
 machine_subsys_initcall(powernv, opal_init);
@@ -966,6 +969,7 @@ int opal_error_code(int rc)
 	case OPAL_UNSUPPORTED:		return -EIO;
 	case OPAL_HARDWARE:		return -EIO;
 	case OPAL_INTERNAL_ERROR:	return -EIO;
+	case OPAL_TIMEOUT:		return -ETIMEDOUT;
 	default:
 		pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
 		return -EIO;