Add comment on g_tree_len > 0.

libraries/base/common/src/vhdl/common_fifo_dc.vhd

@@ -76,7 +76,7 @@ begin
   generic map (
     g_rst_level => '1',
     g_delay_len => 3,
-    g_tree_len  => 0
+    g_tree_len  => 0  -- assume if necessary g_tree_len > 0 is covered via input rst
   )
   port map (
     in_rst    => rst,

libraries/base/common/src/vhdl/common_fifo_dc_mixed_widths.vhd

@@ -95,7 +95,7 @@ begin
   generic map (
     g_rst_level => '1',
     g_delay_len => 3,
-    g_tree_len  => 0
+    g_tree_len  => 0  -- assume if necessary g_tree_len > 0 is covered via input rst
   )
   port map (
     in_rst    => rst,

libraries/base/common/src/vhdl/common_fifo_sc.vhd

@@ -84,7 +84,7 @@ begin
     generic map (
       g_rst_level => '1',
       g_delay_len => 4,
-      g_tree_len  => 0
+      g_tree_len  => 0  -- assume if necessary g_tree_len > 0 is covered via input rst
     )
     port map (
       in_rst    => rst,