I can't find any similar assembly language module providing descriptor data for PSoC5LP.
The following information may be useful:
The Save button in USBFS component avialable in PSoC5LP allows you to save information about the component configuration into an XML configuration file.
The Component provide an option to handle vendor specific requests. But you need to implement required requests processing in FW. Here is extract from datasheet:
Handle vendor requests in user code
The Component provides an empty vendor request handler (available in the USBFS_vnd.c file) for unsupported vendor requests. This parameter overrides the vendor request handler function with a user implementation. The USBFS_HandleVendorRqst() function must be implemented by the user to service incoming vendor requests. This function is invoked whenever the vendor request is received and must return with an indication on whether it was handled or not. This option is unchecked by default.
You can check this AN too page#63 for understanding the streamer app usage with PSoC5LP: