drm/amdgpu: move poll enabled/disable into non DC path

Some amd asics having reliable hotplug support don't call
drm_kms_helper_poll_init in driver init sequence. However,
due to the unified suspend/resume path for all asics, because
the output_poll_work->func is not set for these asics, a warning
arrives when suspending.

[ 90.656049] <TASK>
[ 90.656050] ? console_unlock+0x4d/0x100
[ 90.656053] ? __irq_work_queue_local+0x27/0x60
[ 90.656056] ? irq_work_queue+0x2b/0x50
[ 90.656057] ? __wake_up_klogd+0x40/0x60
[ 90.656059] __cancel_work_timer+0xed/0x180
[ 90.656061] drm_kms_helper_poll_disable.cold+0x1f/0x2c [drm_kms_helper]
[ 90.656072] amdgpu_device_suspend+0x81/0x170 [amdgpu]
[ 90.656180] amdgpu_pmops_runtime_suspend+0xb5/0x1b0 [amdgpu]
[ 90.656269] pci_pm_runtime_suspend+0x61/0x1b0

drm_kms_helper_poll_enable/disable is valid when poll_init is called in
amdgpu code, which is only used in non DC path. So move such codes into
non-DC path code to get rid of such warnings.

v1: introduce use_kms_poll flag in amdgpu as the poll stuff check
v2: use dc_enabled as the flag to simply code
v3: move code into non DC path instead of relying on any flag

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2411
Fixes: a4e771729a51 ("drm/probe_helper: sort out poll_running vs poll_enabled")
Reported-by: Bert Karwatzki <[e-mail]>
Suggested-by: Dmitry Baryshkov <[e-mail]>
Suggested-by: Alex Deucher <[e-mail]>
Signed-off-by: Guchun Chen <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>
Cc: [e-mail]

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

···
 	if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D3))
 		DRM_WARN("smart shift update failed\n");
 
-	drm_kms_helper_poll_disable(dev);
-
 	if (fbcon)
 		drm_fb_helper_set_suspend_unlocked(adev_to_drm(adev)->fb_helper, true);
 
···
 
 	if (fbcon)
 		drm_fb_helper_set_suspend_unlocked(adev_to_drm(adev)->fb_helper, false);
-
-	drm_kms_helper_poll_enable(dev);
 
 	amdgpu_ras_resume(adev);
 

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

···
 	struct drm_connector_list_iter iter;
 	int r;
 
+	drm_kms_helper_poll_disable(dev);
+
 	/* turn off display hw */
 	drm_modeset_lock_all(dev);
 	drm_connector_list_iter_begin(dev, &iter);
···
 	drm_connector_list_iter_end(&iter);
 
 	drm_modeset_unlock_all(dev);
+
+	drm_kms_helper_poll_enable(dev);
 
 	return 0;
 }