pcsc-cyberjack: Also install cjflash tool

This tool is necessary in order to update the firmware of the secoder.

The reason I've added this to a separate output "tools" is because it
clearly is not relevant for the PCSC driver itself and it's also very
rarely needed.

I've also verified wether the closure of the PCSC plugin env still only
contains the main output and that's the case.

There are also other tools - cjBingoTest and cjgeldkarte, where the
former doesn't compile due to cjeca32.h not being found and cjgeldkarte,
which does compile but tries to dlopen() the library and subsequently
fails.

Both of these tools however look like they're just performing tests and
are not very useful outside of development, so I opted to not include
them.

Signed-off-by: aszlig <aszlig@nix.build>