software: Manual review and cleanup of generated reqts

Performed a manual review and cleanup of the generated requirements.
Compared the requirements to the Mailboxes documentation page for
functionality. Generalized the requirements to remove function names.

signed-off-by: Joel Key <[email protected]>

Author: jkey-eng

docs/software_requirements/index.sdoc

@@ -71,4 +71,4 @@ FILE: tracing.sdoc
 FILE: condition_variables.sdoc
 
 [DOCUMENT_FROM_FILE]
-FILE: mailbox.sdoc
+FILE: mailboxes.sdoc