Update profiles for API 68.13.7.

Signed-off-by: Nuno Sa <[email protected]>
(cherry picked from commit fdb2f83)

Add an API to only update the gui value of a specific widget. This is
useful when we have to do the actual attribute reading before we need to
update the GUI.

In the next patch, we'll introduce an user of this API.

Signed-off-by: Nuno Sa <[email protected]>
(cherry picked from commit 4ceed02)

With the changes in the device driver API, reading the RSSI on a channel
that's not enabled will trow an error. Hence, instead of flooding the
device with error's (and the kernel log), don't read the RSSI for
channels that are not enabled.

With the above, as we always need to read the ensm widget, make use
iio_widget_update_value() to update it in case port enable is set to pin
(and hence avoiding another call into the device).

Signed-off-by: Nuno Sa <[email protected]>
(cherry picked from commit 54efaad)