soc: mediatek: mtk-mutex: Replace max handles number with definition

Replace the magic number "10", defining the maximum number of supported
handles with a MTK_MUTEX_MAX_HANDLES definition.
While at it, also change the type for `id` from a signed integer to
a unsigned 8 bits integer to save some (small) memory footprint, as
this number is never higher than 10.

This cleanup brings no functional changes.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20230222094253.23678-7-angelogioacchino.delregno@collabora.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Author: AngeloGioacchino Del Regno

drivers/soc/mediatek/mtk-mutex.c

@@ -14,6 +14,8 @@
 #include <linux/soc/mediatek/mtk-mutex.h>
 #include <linux/soc/mediatek/mtk-cmdq.h>
 
+#define MTK_MUTEX_MAX_HANDLES			10
+
 #define MT2701_MUTEX0_MOD0			0x2c
 #define MT2701_MUTEX0_SOF0			0x30
 #define MT8183_MUTEX0_MOD0			0x30
@@ -282,7 +284,7 @@
 #define MT8195_MUTEX_EOF_DPI1			(MT8195_MUTEX_SOF_DPI1 << 7)
 
 struct mtk_mutex {
-	int id;
+	u8 id;
 	bool claimed;
 };
 
@@ -312,7 +314,7 @@ struct mtk_mutex_ctx {
 	struct device			*dev;
 	struct clk			*clk;
 	void __iomem			*regs;
-	struct mtk_mutex		mutex[10];
+	struct mtk_mutex		mutex[MTK_MUTEX_MAX_HANDLES];
 	const struct mtk_mutex_data	*data;
 	phys_addr_t			addr;
 	struct cmdq_client_reg		cmdq_reg;
@@ -717,7 +719,7 @@ struct mtk_mutex *mtk_mutex_get(struct device *dev)
 	struct mtk_mutex_ctx *mtx = dev_get_drvdata(dev);
 	int i;
 
-	for (i = 0; i < 10; i++)
+	for (i = 0; i < MTK_MUTEX_MAX_HANDLES; i++)
 		if (!mtx->mutex[i].claimed) {
 			mtx->mutex[i].claimed = true;
 			return &mtx->mutex[i];
@@ -1007,7 +1009,7 @@ static int mtk_mutex_probe(struct platform_device *pdev)
 	if (!mtx)
 		return -ENOMEM;
 
-	for (i = 0; i < 10; i++)
+	for (i = 0; i < MTK_MUTEX_MAX_HANDLES; i++)
 		mtx->mutex[i].id = i;
 
 	mtx->data = of_device_get_match_data(dev);