staging: comedi: me_daq: tidy up status register defines

Rename the bits of this register so they have association with the
register. Use the BIT macro to define the bits.

Writing to the status register clears any pending interrupts. For
aesthetics, remove the ME_RESET_INTERRUPT define and just use the
ME_STATUS_REG define to write the register.

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>