staging: comedi: cb_pcidas64: fix forward declarations 3

Move `abort_dma()`, `disable_ai_pacing()`, `i2c_high_udelay`,
`i2c_low_udelay`, `i2c_set_sda()`, `i2c_set_scl()`, `i2c_write_byte()`,
`i2c_read_ack()`, `i2c_start()`, `i2c_stop()`, `i2c_write()`,
`get_divisor()`, `check_adc_timing()`, `disable_ai_pacing()`,
`abort_dma()`, `get_ao_divisor()`, `ao_inttrig()`,
`caldac_8800_write()`, `caldac_i2c_write()`, `check_adc_timing()`,
`get_divisor()`, and `get_ao_divisor()`, and remove their forward
declarations.

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