AHAL: add default values for dynamic port config of hardcoded config.

If the values(format, sample rate, channel mask) are left as unset, they
will be null. In that case, when using them will require checking
nullablitiy to avoid crash.

Bug: 323255506
Test: make and boot
Change-Id: Ic66bf0b6f53750ff8700e531cca13f03fbb72936