* Support new API linalg.cond in paddle

* check code style

* check code style

* modify codes

* add docs_eng of linalg.cond

* add svd_norm for linalg.cond

* modify docs_en of cond

* add support for empty input in dynamic mode

* modify set_time of unittest

* update

* modify unittest of cond

* update

* remove cond in paddle.__all__

* pull latest codes

* merge latest codes

* update