selftests: pp-bench: remove unneeded linux/version.h

selftests: pp-bench: remove unneeded linux/version.h

linux/version.h was used by the out-of-tree version, but not needed in
the upstream one anymore.

While I'm at it, sort the includes.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506271434.Gk0epC9H-lkp@intel.com/
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://patch.msgid.link/20250627200501.1712389-1-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>