staging: comedi: amplc_pci224: remove 'inline' from pci224_gat_config()

Let the compiler figure out whether `pci224_gat_confip()` should be
inlined by itself.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>