mfd: stmfx: Convert to use maple tree register cache

The maple tree register cache is based on a much more modern data structure
than the rbtree cache and makes optimisation choices which are probably
more appropriate for modern systems than those made by the rbtree cache.
Signed-off-by: Bo Liu <liubo03@inspur.com>
Link: https://lore.kernel.org/r/20240206071314.8721-17-liubo03@inspur.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/stmfx.c

@@ -53,7 +53,7 @@ static const struct regmap_config stmfx_regmap_config = {
 	.max_register	= STMFX_REG_MAX,
 	.volatile_reg	= stmfx_reg_volatile,
 	.writeable_reg	= stmfx_reg_writeable,
-	.cache_type	= REGCACHE_RBTREE,
+	.cache_type	= REGCACHE_MAPLE,
 };
 
 static const struct resource stmfx_pinctrl_resources[] = {