device-amazon-biscuit: add alsa and pulseaudio configs

This commit provides a basic pulseaudio setup for biscuit, for both speaker and headphone jack. It only gets acceptable results with 48kHz audio right now using paplay, resampled audio seems to produce a lot of crackle and popping from the audio buffer underflowing, although some tweaks could still be done to improve playback performance.

device/testing/device-amazon-biscuit/ucm2/HiFi.conf

+SectionDevice."Speaker" {
+	Comment "Speaker"
+
+	Value {
+		PlaybackPriority 200
+		PlaybackPCM "hw:${CardId},23"
+		PlaybackRate 48000
+	}
+
+	EnableSequence [
+		cset "name='Ext_Speaker_Amp_Switch' On"
+		cset "name='Ignore Ramp Up' Off"
+		cset "name='Audio_DacMux_Setting' Off"
+		cset "name='Right Channel Only' On"
+		cset "name='HP Driver Gain Volume' 6"
+		cset "name='PCM Playback Volume' 127,127"
+	]
+}
+
+SectionDevice."Headphones" {
+	Comment "Headphones/Line Out"
+
+	Value {
+		PlaybackPriority 100
+		PlaybackPCM "hw:${CardId},23"
+	}
+
+	EnableSequence [
+		cset "name='Ext_Speaker_Amp_Switch' Off"
+		cset "name='Ignore Ramp Up' On"
+		cset "name='HP Driver Gain Volume' 11"
+		cset "name='Audio_DacMux_Setting' On"
+		cset "name='Right Channel Only' Off"
+	]
+}
+