drm/amd/display: fix SUBVP DC_DEBUG_MASK documentation

This needs to be kerneldoc formatted.

Fixes: 5349658fa4a1 ("drm/amd: Add debug option to disable subvp")
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>

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

@@ -350,7 +350,7 @@ enum DC_DEBUG_MASK {
 	 */
 	DC_DISABLE_HDMI_CEC = 0x10000,
 
-	/*
+	/**
 	 * @DC_DISABLE_SUBVP: If set, disable DCN Sub-Viewport feature in amdgpu driver.
 	 */
 	DC_DISABLE_SUBVP = 0x20000,