drm/powerplay/hwmgr: log errors in tonga_hwmgr_backend_init

BugLink: http://bugs.launchpad.net/bugs/1546572

Helpful in debugging init issues.
Reviewed-by: Tom St Denis <tom.stdenis@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit aa22ae4b)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/gpu/drm/amd/powerplay/hwmgr/tonga_hwmgr.c

@@ -4557,6 +4557,8 @@ int tonga_hwmgr_backend_init(struct pp_hwmgr *hwmgr)
 
 	/* Initalize Dynamic State Adjustment Rule Settings*/
 	result = tonga_initializa_dynamic_state_adjustment_rule_settings(hwmgr);
+	if (result)
+		printk(KERN_ERR "[ powerplay ] tonga_initializa_dynamic_state_adjustment_rule_settings failed!\n");
 	data->uvd_enabled = 0;
 
 	table = &(data->smc_state_table);