reindex with Period results in NaN
#### Code Sample, a copy-pastable example if possible

```python

idx1 = pd.MultiIndex.from_tuples(
    [
        ("x", Period("2019Q1", "Q-DEC")),
        ("x", Period("2019Q2", "Q-DEC")),
    ]
)

idx2 = pd.MultiIndex.from_tuples(
    [
        ("x", Period("2019Q1", "Q-DEC")),
        ("x", Period("2019Q2", "Q-DEC")),
        ("x", "All"),
    ]
)

s = pd.Series([1.0, 1.0], index=idx1)

x  2019Q1    1.0
   2019Q2    1.0
dtype: float64

# ACTUAL

s.reindex(idx2)

x  2019Q1   NaN
   2019Q2   NaN
   All      NaN
dtype: float64

# EXPECTED

x  2019Q1   1.0
   2019Q2   1.0
   All      NaN
dtype: float64


```
#### Problem description

This is the underlying problem causing https://github.com/pandas-dev/pandas/issues/28323.  Reindexing with an index that contains a Period results in `NaN` results.

#### Output of ``pd.show_versions()``

<details>

INSTALLED VERSIONS
------------------
commit           : None
python           : 3.7.4.final.0
python-bits      : 64
OS               : Windows
OS-release       : 10
machine          : AMD64
processor        : Intel64 Family 6 Model 94 Stepping 3, GenuineIntel
byteorder        : little
LC_ALL           : None
LANG             : None
LOCALE           : None.None

pandas           : 0.25.1
numpy            : 1.17.2
pytz             : 2019.2
dateutil         : 2.8.0
pip              : 19.2.2
setuptools       : 41.0.1
Cython           : None
pytest           : None
hypothesis       : None
sphinx           : None
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : None
html5lib         : None
pymysql          : None
psycopg2         : None
jinja2           : 2.10.1
IPython          : 7.8.0
pandas_datareader: None
bs4              : None
bottleneck       : None
fastparquet      : None
gcsfs            : None
lxml.etree       : None
matplotlib       : None
numexpr          : None
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : None
pytables         : None
s3fs             : None
scipy            : None
sqlalchemy       : None
tables           : None
xarray           : None
xlrd             : None
xlwt             : None
xlsxwriter       : None

</details>
