mfd: rn5t618: Fix caching of battery related registers

Battery status changes dynamically, so the corresponding registers
need to be considered volatile. Affected registers are:

 - fuel gauge
 - battery status
 - battery interrupt

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
1 file changed