[clang-tidy] Move google-readability-function check to readability-named-parameter.

Summary: The relevant style rule is going to be removed, thus the check is no longer needed in the Google module. Leaving the check in readability/ in case someone needs it.

Reviewers: djasper

Reviewed By: djasper

Subscribers: curdeius, cfe-commits

Differential Revision: http://reviews.llvm.org/D8261

llvm-svn: 232431