Export maximum affinity using PLATFORM_MAX_AFFLVL macro

This patch removes the plat_get_max_afflvl() platform API
and instead replaces it with a platform macro PLATFORM_MAX_AFFLVL.
This is done because the maximum affinity level for a platform
is a static value and it is more efficient for it to be defined
as a platform macro.

NOTE: PLATFORM PORTS NEED TO BE UPDATED ON MERGE OF THIS COMMIT

Fixes ARM-Software/tf-issues#265

Change-Id: I31d89b30c2ccda30d28271154d869060d50df7bf
diff --git a/services/std_svc/psci/psci_setup.c b/services/std_svc/psci/psci_setup.c
index 02a8786..5ff24d5 100644
--- a/services/std_svc/psci/psci_setup.c
+++ b/services/std_svc/psci/psci_setup.c
@@ -107,7 +107,7 @@
 {
 	int rc;
 
-	if (aff_lvl > get_max_afflvl())
+	if (aff_lvl > PLATFORM_MAX_AFFLVL)
 		return NULL;
 
 	/* Right shift the mpidr to the required affinity level */
@@ -320,7 +320,7 @@
 	psci_plat_pm_ops = NULL;
 
 	/* Find out the maximum affinity level that the platform implements */
-	max_afflvl = get_max_afflvl();
+	max_afflvl = PLATFORM_MAX_AFFLVL;
 	assert(max_afflvl <= MPIDR_MAX_AFFLVL);
 
 	/*