[media] rtl28xxu: use muxed RTL2832 I2C adapters for E4000 and RTL2832_SDR

RTL2832 driver provides muxed I2C adapters for tuner bus I2C gate
control. Pass those adapters to rtl2832_sdr and e4000 modules in order
to get rid of proprietary DVB .i2c_gate_ctrl() callback use.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>