drm/amdgpu: add amdgpu.powerplay module option

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

This option can be used to enable the new powerplay implementation,
and it is disabled by default.
Signed-off-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 3a74f6f2)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -165,6 +165,11 @@ module_param_named(sched_hw_submission, amdgpu_sched_hw_submission, int, 0444);
 MODULE_PARM_DESC(enable_semaphores, "Enable semaphores (1 = enable, 0 = disable (default))");
 module_param_named(enable_semaphores, amdgpu_enable_semaphores, int, 0644);
 
+#ifdef CONFIG_DRM_AMD_POWERPLAY
+MODULE_PARM_DESC(powerplay, "Powerplay component (1 = enable, 0 = disable (default))");
+module_param_named(powerplay, amdgpu_powerplay, int, 0444);
+#endif
+
 static struct pci_device_id pciidlist[] = {
 #ifdef CONFIG_DRM_AMDGPU_CIK
 	/* Kaveri */