Add Addressmap block size to generated package (#134)

* add map size as a localparam in rdl map package

* rename from _SIZE -> _BYTES_SIZE

* fix names on new test & localparam

* wrap map size in SVInt

tests/test_map_size/regblock.rdl

@@ -0,0 +1,5 @@
+addrmap top {
+    reg {
+        field {} f1[32] = 0;
+    } my_reg;
+};