[flang] Add team_type to num_images intrinsic call

num_images had previously been added to the list of intrinsics
before the type team_type had been implemented. Now that team_type
is implemented, add the num_images call that has the team argument.
Update the semantics tests for num_images.

Reviewed By: craig.rasmussen

Differential Revision: https://reviews.llvm.org/D126734