Rework state management in the PSCI implementation

This patch pulls out state management from the affinity level specific handlers
into the top level functions specific to the operation
i.e. psci_afflvl_suspend(), psci_afflvl_on() etc.

In the power down path this patch will allow an affinity instance at level X to
determine the state that an affinity instance at level X+1 will enter before the
level specific handlers are called. This will be useful to determine whether a
CPU is the last in the cluster during a suspend/off request and so on.

Similarly, in the power up path this patch will allow an affinity instance at
level X to determine the state that an affinity instance at level X+1 has
emerged from, even after the level specific handlers have been called. This will
be useful in determining whether a CPU is the first in the cluster during a
on/resume request and so on.

As before, while powering down, state is updated before the level specific
handlers are invoked so that they can perform actions based upon their target
state. While powering up, state is updated after the level specific handlers have
been invoked so that they can perform actions based upon the state they emerged
from.

Change-Id: I40fe64cb61bb096c66f88f6d493a1931243cfd37
diff --git a/services/std_svc/psci/psci_private.h b/services/std_svc/psci/psci_private.h
index 158a5f7..73690b8 100644
--- a/services/std_svc/psci/psci_private.h
+++ b/services/std_svc/psci/psci_private.h
@@ -92,6 +92,10 @@
 		       uint64_t entrypoint, uint64_t context_id,
 		       uint32_t caller_scr_el3, uint32_t caller_sctlr_el1);
 int psci_check_afflvl_range(int start_afflvl, int end_afflvl);
+void psci_do_afflvl_state_mgmt(uint32_t start_afflvl,
+			       uint32_t end_afflvl,
+			       mpidr_aff_map_nodes_t mpidr_nodes,
+			       uint32_t state);
 void psci_acquire_afflvl_locks(int start_afflvl,
 				int end_afflvl,
 				mpidr_aff_map_nodes_t mpidr_nodes);