Update generation_logits_process.py (#12671)

If you're using type hints, then passing an `int` where a `float` is annotated is acceptable as per [PEP 484](https://www.python.org/dev/peps/pep-0484/#the-numeric-tower).

This makes life a little nicer.

src/transformers/generation_logits_process.py

@@ -184,7 +184,8 @@ class TopPLogitsWarper(LogitsWarper):
     """
 
     def __init__(self, top_p: float, filter_value: float = -float("Inf"), min_tokens_to_keep: int = 1):
-        if not isinstance(top_p, float) or (top_p < 0 or top_p > 1.0):
+        top_p = float(top_p)
+        if top_p < 0 or top_p > 1.0:
             raise ValueError(f"`top_p` has to be a float > 0 and < 1, but is {top_p}")
 
         self.top_p = top_p