ASoC: fsl_micfil: Add Hardware Voice Activity Detector support

The Hardware Voice Activity Detector (HWVAD) is a block
responsible for detect voice activity in a channel selected
by the user. It can be configured in Envelope-based or
Energy-based mode.

There are additional two interrupts for HWVAD, one is event
interrupt, another is error interrupt.

Enable hwvad in parallel with recording.
when voice activity detected, HWVAD will be disabled and
alsa control notification is triggerred.
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1663925494-9941-1-git-send-email-shengjiu.wang@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_micfil.h

@@ -136,10 +136,14 @@
 #define FIFO_PTRWID			3
 #define FIFO_LEN			BIT(FIFO_PTRWID)
 
-#define MICFIL_IRQ_LINES		2
+#define MICFIL_IRQ_LINES		4
 #define MICFIL_MAX_RETRY		25
 #define MICFIL_SLEEP_MIN		90000 /* in us */
 #define MICFIL_SLEEP_MAX		100000 /* in us */
 #define MICFIL_DMA_MAXBURST_RX		6
 
+/* HWVAD Constants */
+#define MICFIL_HWVAD_ENVELOPE_MODE	0
+#define MICFIL_HWVAD_ENERGY_MODE	1
+
 #endif /* _FSL_MICFIL_H */