rtc: ab-eoz9: set regmap max_register

Set regmap's max_register property to allow users to dump registers
using debufgs.

Signed-off-by: Liam Beguin <lvb@xiphos.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210408024028.3526564-2-liambeguin@gmail.com

drivers/rtc/rtc-ab-eoz9.c

@@ -264,6 +264,7 @@ static const struct rtc_class_ops rtc_ops = {
 static const struct regmap_config abeoz9_rtc_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
+	.max_register = 0x3f,
 };
 
 #if IS_REACHABLE(CONFIG_HWMON)