doc: extensions: Add support for space delimited shields

In case an entry takes multiple shileds delimited by space, handle that
by moving to a list based parsing from string based parsing.

Signed-off-by: Chaitanya Tata <Chaitanya.Tata@nordicsemi.no>

Author: krish2718

doc/_extensions/table_from_rows.py

@@ -180,12 +180,12 @@ def _find_shields(shields: Dict[str, Set[str]], sample_data: dict):
         if not extra_args_raw:
             return
 
-        if isinstance(extra_args_raw, list):
-            extra_args = " ".join(extra_args_raw)
+        if isinstance(extra_args_raw, str):
+            extra_args = extra_args_raw.split()
         else:
             extra_args = extra_args_raw
 
-        shield_args = re.findall(r'SHIELD=(\S*)', extra_args)
+        shield_args = [re.split(r'=', arg)[1] for arg in extra_args if 'SHIELD=' in arg]
         if not shield_args:
             return