gcc-plugins: Change all version strings match kernel

gcc-plugins: Change all version strings match kernel

It's not meaningful for the GCC plugins to track their versions separately
from the rest of the kernel. Switch all versions to the kernel version.

Fix mismatched indenting while we're at it.

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>