ASoC: rsnd: Fix RSND_SOC_MASK width to single nibble

RSND_SOC_MASK was defined as (0xFF << 4), spanning bits 4-11. This is
wider than needed since only nibble B (bits 7:4) is used for SoC
identifiers. Narrow it to (0xF << 4) to match the intended single-nibble
allocation and prevent overlap with bits 8-11 which will be used by
upcoming RZ series flags.

No functional change, since the only current user (RSND_SOC_E) fits
within a single nibble.

Fixes: ba164a4 ("ASoC: rsnd: src: Avoid a potential deadlock")
Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/20260525110230.4014435-3-john.madieu.xa@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: John Madieu

sound/soc/renesas/rcar/rsnd.h

@@ -624,7 +624,7 @@ struct rsnd_priv {
 #define RSND_GEN2	(2 << 0)
 #define RSND_GEN3	(3 << 0)
 #define RSND_GEN4	(4 << 0)
-#define RSND_SOC_MASK	(0xFF << 4)
+#define RSND_SOC_MASK	(0xF << 4)
 #define RSND_SOC_E	(1 << 4) /* E1/E2/E3 */
 
 	/*