It seems that on this board, the demodulator provides the pullup on the I2C
bus, which means that calling i2c_gate_ctrl crashes the bus.  Turn this off
and the xc3028 can talk OK.  Also fix some GPIO related settings that
became more clear through working on this.

Some changes made by Mauro Chehab to allow merging it with some
other xc3028 patches.
Signed-off-by: Chris Pascoe <c.pascoe@itee.uq.edu.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>