[SCSI] aci7xxx_old: delete decade+ obsolete driver

After getting warnings in an allyesconfig build[1] from this
driver, I decided to remind myself just how old it was, and
whether it warranted fixing.  In the Kconfig help text, I found:

  "This driver will eventually be phased out entirely"

Going back to the history archive, I see the line was added[2]
in Feb 2002, when we moved from v2.4.2.1 ---> v2.4.2.2

So, with over a decade of notification, and multiple major releases
since then, I think we can justify removing this.  Currently we have
people wasting time building it during routine testing, and then
wasting more time re-researching the known reported warnings, only to
find that nobody really is willing to integrate the fixes[3] for it.

A quick search didn't seem to indicate any active user base for it.
If someone happens to have a quirky _old_ card that the eleven year
old "new" driver doesn't work with, then it is entirely reasonable
that they stick with a kernel version that predates this removal.

[1] drivers/scsi/aic7xxx_old.c: In function ‘aic7xxx_register’:
    drivers/scsi/aic7xxx_old.c:7901:5: warning: case value ‘257’ not in enumerated type ‘ahc_chip’ [-Wswitch]
    drivers/scsi/aic7xxx_old.c:7898:5: warning: case value ‘513’ not in enumerated type ‘ahc_chip’ [-Wswitch]
    drivers/scsi/aic7xxx_old.c: In function ‘aic7xxx_load_seeprom’:
    drivers/scsi/aic7xxx_old.c:8517:5: warning: case value ‘257’ not in enumerated type ‘ahc_chip’ [-Wswitch]
    drivers/scsi/aic7xxx_old.c:8510:5: warning: case value ‘513’ not in enumerated type ‘ahc_chip’ [-Wswitch]

[2] http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git commit 44e8778c

[3] https://lkml.org/lkml/2012/10/29/215



Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>