drm/radeon: fix ATPX function documentation

Fix a copy&pasted documentation.

Signed-off-by: Igor Murzov <e-mail@date.by>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_atpx_handler.c b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
index 37f6a90..15f5ded 100644
--- a/drivers/gpu/drm/radeon/radeon_atpx_handler.c
+++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
@@ -352,9 +352,9 @@
 }
 
 /**
- * radeon_atpx_switchto - switch to the requested GPU
+ * radeon_atpx_power_state - power down/up the requested GPU
  *
- * @id: GPU to switch to
+ * @id: GPU to power down/up
  * @state: requested power state (0 = off, 1 = on)
  *
  * Execute the necessary ATPX function to power down/up the discrete GPU