staging: gpib: Make GPIB_NI_PCI_ISA depend on HAS_IOPORT

staging: gpib: Make GPIB_NI_PCI_ISA depend on HAS_IOPORT

After commit 78ecb0375685 ("staging: gpib: make port I/O code
conditional"), building tnt4882.ko on platforms without HAS_IOPORT (such
as hexagon and s390) fails with:

  ERROR: modpost: "inb_wrapper" [drivers/staging/gpib/tnt4882/tnt4882.ko] undefined!
  ERROR: modpost: "inw_wrapper" [drivers/staging/gpib/tnt4882/tnt4882.ko] undefined!
  ERROR: modpost: "nec7210_locking_ioport_write_byte" [drivers/staging/gpib/tnt4882/tnt4882.ko] undefined!
  ERROR: modpost: "nec7210_locking_ioport_read_byte" [drivers/staging/gpib/tnt4882/tnt4882.ko] undefined!
  ERROR: modpost: "outb_wrapper" [drivers/staging/gpib/tnt4882/tnt4882.ko] undefined!
  ERROR: modpost: "outw_wrapper" [drivers/staging/gpib/tnt4882/tnt4882.ko] undefined!

Only allow tnt4882.ko to be built when CONFIG_HAS_IOPORT is set to avoid
this build failure, as this driver unconditionally needs it.

Fixes: 78ecb0375685 ("staging: gpib: make port I/O code conditional")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20241123-gpib-tnt4882-depends-on-has_ioport-v1-1-033c58b64751@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>