Remove defaults for a bunch of volatile registers and remove
ARIZONA_CTRL_IF_SPI_CFG_1 from the readable list since it doesn't exist
on wm8998 which is I2C only.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>