i2c: Delete unused adapter IDs

Delete unused I2C adapter IDs. Special cases are:

* I2C_HW_B_RIVA was still set in driver rivafb, however no other
  driver is ever looking for this value, so we can safely remove it.
* I2C_HW_B_HDPVR is used in staging driver lirc_zilog, however no
  adapter ID is ever set to this value, so the code in question never
  runs. As the code additionally expects that I2C_HW_B_HDPVR may not
  be defined, we can delete it now and let the lirc_zilog driver
  maintainer rewrite this piece of code.

Big thanks for Hans Verkuil for doing all the hard work :)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>