The ISO configs set defaults based upon BT_ISO_MAX_CHAN and other
configs defined in `bluetooth/Kconfig.iso`.
By adding these dependencies the error messages resulting from
adding `CONFIG_BT_CTLR_PERIPHERAL_ISO=y` to a project configuration
file will become less confusing.
Now the build will output:
```
warning: BT_CTLR_PERIPHERAL_ISO (
defined at subsys/bluetooth/controller/Kconfig:976,
subsys/bluetooth/controller/Kconfig:984) was assigned the value 'y' but
got the value 'n'. See ...
```
Previously we would get:
```
warning: default value 0 on BT_CTLR_CONN_ISO_STREAMS
(defined at subsys/bluetooth/controller/Kconfig:993)
clamped to 1 due to being outside the active range ([1, 64])
```
Signed-off-by: Rubin Gerritsen <rubin.gerritsen@nordicsemi.no>
65c7f1f269