staging;gpib: Use Kconfig PCMCIA compilation symbol

staging;gpib: Use Kconfig PCMCIA compilation symbol

The drivers supporting the PCMCIA bus were using an intermediate
symbol GPIB_PCMCIA for compiling optional PCMCIA support.
This symbol is no longer needed for the in-tree drivers as the
Kconfig symbol is available.

Use the Kconfig symbol CONFIG_GPIB_PCMCIA directly for conditional
compilation of PCMCIA support.

Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20250210151022.4358-2-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>