[flang][OpenMP] Allow UPDATE clause to not have any arguments (#137521)

The UPDATE clause can be specified on both ATOMIC and DEPOBJ directives.
Currently, the ATOMIC directive has its own handling of it, and the
definition of the UPDATE clause only supports its use in the DEPOBJ
directive, where it takes a dependence-type as an argument.

The UPDATE clause on the ATOMIC directive may not have any arguments.
Since the implementation of the ATOMIC construct will be modified to use
the standard handling of clauses, the definition of UPDATE should
reflect that.

0 files changed, 0 insertions, 0 deletions