drm/amd/display: fix CEC DC_DEBUG_MASK documentation

This needs to be kerneldoc formatted.

Fixes: 7594874227e1 ("drm/amd/display: add CEC notifier to amdgpu driver")
Reported-by: Stephen Rothwell <[e-mail]>
Reviewed-by: Harry Wentland <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>
Cc: Kun Liu <[e-mail]>

drivers/gpu/drm/amd/include/amd_shared.h

···
 	 */
 	DC_DISABLE_ACPI_EDID = 0x8000,
 
-	/*
+	/**
 	 * @DC_DISABLE_HDMI_CEC: If set, disable HDMI-CEC feature in amdgpu driver.
 	 */
 	DC_DISABLE_HDMI_CEC = 0x10000,