minimize BRAM usage by dropping unused gens and using int4 instead of full-speed

QICK running on ZCU111, software version 0.2.289

Firmware configuration (built Wed Oct  2 13:31:41 2024):

	Global clocks (MHz): tProcessor 409.600, RF reference 204.800

	1 signal generator channels:
	0:	axis_sg_int4_v2 - envelope memory 1024 samples (2.500 us)
		fs=6553.600 MHz, fabric=409.600 MHz, 32-bit DDS, range=1638.400 MHz
		DAC tile 0, blk 0 is DAC228_T0_CH0 or RF board output 0

	0 readout channels:

	8 digital output pins:
	0:	PMOD0_0
	1:	PMOD0_1
	2:	PMOD0_2
	3:	PMOD0_3
	4:	PMOD0_4
	5:	PMOD0_5
	6:	PMOD0_6
	7:	PMOD0_7

	tProc qick_processor ("v2") rev 21: program memory 256 words, data memory 256 words
		external start pin: None