iio: light: opt4060: Switch to sparse friendly iio_device_claim/release_direct()

iio: light: opt4060: Switch to sparse friendly iio_device_claim/release_direct()

These new functions allow sparse to find failures to release
direct mode reducing chances of bugs over the claim_direct_mode()
functions that are deprecated.  This is a case where the code
is pinning down the mode so also has a claim on buffered mode.
A follow up set may move those calls over to a sparse friendly
form as well.

Tested-by: Per-Daniel Olsson <perdaniel.olsson@axis.com>
Reviewed-by: Per-Daniel Olsson <perdaniel.olsson@axis.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250309170633.1347476-10-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>