asix-sigma: rephrase submission of logic data to session feed

asix-sigma: rephrase submission of logic data to session feed

Introduce a 4MiB session feed submission buffer in the device context.
This reduces the number of API calls and improves performance of srzip
archive creation.

This change also eliminates complex logic which manipulates a previously
created buffer's length and data position, to split the queued data when
a trigger position was involed. The changed implementation results in a
data flow from sample memory to the session feed which feels more natural
during review, and better lends itself to future trigger support code.

Use common SW limits support for the optional sample count limit. Move
'sdi' and 'devc' parameters to the front to match conventions. Reduce
indentation in routine signatures while we are here.

This implementation is prepared to handle trigger positions, but for now
disables the specific logic which checks for trigger condition matches
to improve the trigger marker's resolution. This will get re-enabled in
a later commit.