mfd: rc5t583: 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 <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/rc5t583.c

···
 	.volatile_reg = volatile_reg,
 	.max_register = RC5T583_MAX_REG,
 	.num_reg_defaults_raw = RC5T583_NUM_REGS,
-	.cache_type = REGCACHE_RBTREE,
+	.cache_type = REGCACHE_MAPLE,
 };
 
 static int rc5t583_i2c_probe(struct i2c_client *i2c)