drm/amdgpu: add a message to indicate when powerplay is enabled (v2)

Makes it clear to the user which power management path is in
use.

v2: make consistent with dpm
Reviewed-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Tom St Denis <tom.stdenis@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/amd_powerplay.c

@@ -64,6 +64,11 @@ static int pp_sw_init(void *handle)
 	if (ret == 0)
 		ret = hwmgr->hwmgr_func->backend_init(hwmgr);
 
+	if (ret)
+		printk("amdgpu: powerplay initialization failed\n");
+	else
+		printk("amdgpu: powerplay initialized\n");
+
 	return ret;
 }