staging: comedi: addi_apci_3120: use amcc_s5933.h defines

Use the defines for the AMCC 5933 PCI controller registers and bits instead
of creating private defines in this driver.

Move the generic AGCSTS_TC_ENABLE define from this driver to the header.

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