tools: ynl: render event op docs correctly

The docs for YNL event ops currently render raw python structs. For
example in:

https://docs.kernel.org/netlink/specs/ethtool.html#cable-test-ntf

event: {‘attributes’: [‘header’, ‘status’, ‘nest’], ‘__lineno__’: 2385}

Handle event ops correctly and render their op attributes:

event: attributes: [header, status]

Signed-off-by: Donald Hunter <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/net/ynl/pyynl/lib/doc_generator.py

···
                 continue
             lines.append(self.fmt.rst_paragraph(self.fmt.bold(key), level + 1))
             if key in ['request', 'reply']:
-                lines.append(self.parse_do_attributes(do_dict[key], level + 1) + "\n")
+                lines.append(self.parse_op_attributes(do_dict[key], level + 1) + "\n")
             else:
                 lines.append(self.fmt.headroom(level + 2) + do_dict[key] + "\n")
 
         return "\n".join(lines)
 
-    def parse_do_attributes(self, attrs: Dict[str, Any], level: int = 0) -> str:
+    def parse_op_attributes(self, attrs: Dict[str, Any], level: int = 0) -> str:
         """Parse 'attributes' section"""
         if "attributes" not in attrs:
             return ""
···
 
     def parse_operations(self, operations: List[Dict[str, Any]], namespace: str) -> str:
         """Parse operations block"""
-        preprocessed = ["name", "doc", "title", "do", "dump", "flags"]
+        preprocessed = ["name", "doc", "title", "do", "dump", "flags", "event"]
         linkable = ["fixed-header", "attribute-set"]
         lines = []
 
···
             if "dump" in operation:
                 lines.append(self.fmt.rst_paragraph(":dump:", 0))
                 lines.append(self.parse_do(operation["dump"], 0))
+            if "event" in operation:
+                lines.append(self.fmt.rst_paragraph(":event:", 0))
+                lines.append(self.parse_op_attributes(operation["event"], 0))
 
             # New line after fields
             lines.append("\n")