Add c_eth_tester_reg_hdr_dat_addr_span.

libraries/io/eth/src/vhdl/eth_tester_pkg.vhd

@@ -82,7 +82,8 @@ PACKAGE eth_tester_pkg is
       ( field_name_pad("dp_sync"                                 ), "RW",  1, field_default(0) ),
       ( field_name_pad("dp_bsn"                                  ), "RW", 64, field_default(0) )
   );
-  CONSTANT c_eth_tester_reg_hdr_dat_addr_w : NATURAL := ceil_log2(field_nof_words(c_eth_tester_hdr_field_arr, c_word_w));
+  CONSTANT c_eth_tester_reg_hdr_dat_addr_w    : NATURAL := ceil_log2(field_nof_words(c_eth_tester_hdr_field_arr, c_word_w));  -- = 5
+  CONSTANT c_eth_tester_reg_hdr_dat_addr_span : NATURAL := 2**c_eth_tester_reg_hdr_dat_addr_w;  -- = 32
 
   CONSTANT c_eth_tester_app_hdr_len  : NATURAL :=  12;  -- octets