Added host buffer allowance and stream configuration for Napatech 3GD

Added a napatech section in the yaml configuration.
	hba - host buffer allowance
	use-all-streams - whether all streams should be used
	streams - list of stream numbers to use when use-all-streams is no

The source-napatech.* files were modified to support the host buffer allowance configuration.
The runmode-napatech.c file was modified to support both the host buffer allowance configuration and stream configuration

Signed-off-by: Matt Keeler <mk@npulsetech.com>