[topgen] Inter-module validation code

topgen didn't have a validation code for inter-module signal.
This commit is to implement basic signal format part for inter_module.
It checks below:

1. Check if req/rsp format is `module.signal{[index]}` ({} means
   optional)
2. Check if request is array and matched with the total width of
   responders
3. Check if response has an array index, and request is not an array

Signed-off-by: Eunchan Kim <eunchan@opentitan.org>
diff --git a/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson b/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson
index c4c83f8..1817760 100644
--- a/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson
+++ b/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson
@@ -312,6 +312,7 @@
           act: requester
           package: flash_ctrl_pkg
           inst_name: flash_ctrl
+          width: 1
           top_signame: flash_ctrl_eflash_flash
         }
       ]
@@ -760,6 +761,7 @@
           name: flash_ctrl
           act: responder
           inst_name: eflash
+          width: 1
           top_signame: flash_ctrl_eflash_flash
         }
       ]
@@ -1733,6 +1735,7 @@
         act: requester
         package: flash_ctrl_pkg
         inst_name: flash_ctrl
+        width: 1
         top_signame: flash_ctrl_eflash_flash
       }
       {
@@ -1741,6 +1744,7 @@
         name: flash_ctrl
         act: responder
         inst_name: eflash
+        width: 1
         top_signame: flash_ctrl_eflash_flash
       }
     ]