move axi-wb bridge to dedicated dir for AXI

modules/axi/Manifest.py

 modules = { "local" : [
     "z7_axi_gpio_expander",
+    "axi4lite_wb_bridge",
     ]}
 
 files = [

modules/axi/axi4lite_wb_bridge/Manifest.py

+files = [
+    "xaxi4lite_wb_bridge.vhd",
+];

modules/wishbone/wb_axi4lite_bridge/Manifest.py

 files = [
     "wb_axi4lite_bridge.vhd",
     "xwb_axi4lite_bridge.vhd",
-    "xaxi4lite_wb_bridge.vhd"
 ]