mfd: tps6586x: Fix up define for TPS6586X_MAX_REGISTER

The latest valid register is TPS6586X_VERSIONCRC.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/tps6586x.c b/drivers/mfd/tps6586x.c
index e0a2583..ae08b29 100644
--- a/drivers/mfd/tps6586x.c
+++ b/drivers/mfd/tps6586x.c
@@ -52,7 +52,7 @@
 #define TPS6586X_VERSIONCRC	0xcd
 
 /* Maximum register */
-#define TPS6586X_MAX_REGISTER	(TPS6586X_VERSIONCRC + 1)
+#define TPS6586X_MAX_REGISTER	TPS6586X_VERSIONCRC
 
 struct tps6586x_irq_data {
 	u8	mask_reg;
@@ -467,7 +467,7 @@
 static const struct regmap_config tps6586x_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
-	.max_register = TPS6586X_MAX_REGISTER - 1,
+	.max_register = TPS6586X_MAX_REGISTER,
 	.volatile_reg = is_volatile_reg,
 	.cache_type = REGCACHE_RBTREE,
 };