drivers/iio/adc/ad9361: Fix AD9364 and AD9361 1RX1TX support

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
drivers/iio/adc/ad9361: BIST tone allow setting the frequency bits directly

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>