ASoC: SDCA: mask Function_Status value

According to the SDCA specification [1], when writing Function_Status during
handling this control, the value should mask off bit 7.

[1] MIPI Specification for SoundWire Device Class for Audio, version
    1.1, section 7.14.1.3 (Host Software Handling of Function_Status)

Signed-off-by: Maciej Strozek <mstrozek@opensource.cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20260408093835.2881486-3-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: mstrozek

sound/soc/sdca/sdca_interrupts.c

@@ -138,7 +138,7 @@ static irqreturn_t function_status_handler(int irq, void *data)
 		}
 	}
 
-	ret = regmap_write(interrupt->function_regmap, reg, val);
+	ret = regmap_write(interrupt->function_regmap, reg, val & 0x7F);
 	if (ret < 0) {
 		dev_err(dev, "failed to clear function status: %d\n", ret);
 		goto error;