s390/tape: Consolidate tape config options and modules

s390/tape: Consolidate tape config options and modules

The tape device driver only supports 3490E devices on Virtual Tape Server
(VTS). There is no point in keeping separated options and modules for
different device types and general hardware support. Consolidate the tape
config option into a single option, which enables the complete tape support
with one singular module called 'tape_s390'. The corresponding module entry
points are adapted and consolidate in tape_init() and tape_exit()
respectively in tape_core.c

The current module author and descriptions of the individual tape
modules are outdated and haven't been changed for quite some time.
Change it to a more generic description that is in line with the
corresponding supported s390 architecture for the single tape module.

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>