ASoC: mediatek: mt8186: Remove unused mutex.

The mutex mutex_request_dram has no user.

Remove mutex_request_dram.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230803083908.9DxbPvOK@linutronix.deSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/mt8186/mt8186-afe-clk.c

@@ -13,8 +13,6 @@
 #include "mt8186-afe-clk.h"
 #include "mt8186-audsys-clk.h"
 
-static DEFINE_MUTEX(mutex_request_dram);
-
 static const char *aud_clks[CLK_NUM] = {
 	[CLK_AFE] = "aud_afe_clk",
 	[CLK_DAC] = "aud_dac_clk",