staging: comedi: amplc_pc236: remove PCI device ID macros

The `PCI_DEVICE_ID_AMPLICON_PCI236` macro is only used once, in the
module device table, so remove it and expand the macro in the table.

`The `PCI_DEVICE_ID_INVALID` macro is no longer used, so remove it.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>