This driver code was found as:

https://android.googlesource.com/kernel/tegra/+/aaabb2e045f31e5a970109ffdaae900dd403d17e/drivers/staging/iio/adc

Fixed various compilation issues and test this driver on omap5 evm.
Signed-off-by: NPradeep Goudagunta <pgoudagunta@nvidia.com>
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NMarek Belisko <marek@goldelico.com>
Acked-by: NLaxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: NJonathan Cameron <jic23@kernel.org>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>