mfd: bd70528: Fix hour register mask

mfd: bd70528: Fix hour register mask

commit 6c883472e1c11cb05561b6dd0c28bb037c2bf2de upstream.

When RTC is used in 24H mode (and it is by this driver) the maximum
hour value is 24 in BCD. This occupies bits [5:0] - which means
correct mask for HOUR register is 0x3f not 0x1f. Fix the mask

Fixes: 32a4a4ebf768 ("rtc: bd70528: Initial support for ROHM bd70528 RTC")

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>