ISAPNP: fix limits of logical device register set

PNP_MAX_MEM and PNP_MAX_PORT are mainly used to size tables of PNP
device resources.  In 2.6.24, we increased their values to accomodate
ACPI devices that have many resources:

                 2.6.23    2.6.24
                 ------    ------
  PNP_MAX_MEM       4         12
  PNP_MAX_PORT      8         40

However, ISAPNP also used these constants as the size of parts of the
logical device register set.  This register set is fixed by hardware,
so increasing the constants meant that we were reading and writing
unintended parts of the register set.

This patch changes ISAPNP to use the correct register set sizes (the
same values we used prior to 2.6.24).

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>