I wasn't aware that the unit numbers in the ProDOS device list contain device type...

I wasn't aware that the unit numbers in the ProDOS device list contain device type identifiers in the low nibble. So if we can't use the device list entries as-is we can as well present the high nibble as low nibble to the user thus providing more meaningful device numbers.

git-svn-id: svn://svn.cc65.org/cc65/trunk@5852 b7a2c559-68d2-44c3-8de9-860c34a00d81