[clang][driver] Disable non-functional --version option for clang -cc1

This patch removes --version as a clang -cc1 option.
  clang --version
and
  clang --cc1 -version
remain valid. This behaviour is consistent with clang -cc1as.

Previously, clang -cc1 accepted both --version and -version, but
only -version was acted upon. The call
  clang -cc1 --version
stalled without any message: --version was an accepted option but
triggered no action, and the driver waited for standard input.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D122344