mfd: da9052-spi: Change read-mask to write-mask

Driver has mixed up the R/W bit.
The LSB bit is set on write rather than read.
Change it to avoid nasty things to happen.

Fixes: e9e9d397 ("mfd: da9052: Avoid setting read_flag_mask for da9052-i2c driver")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20240925-da9052-v2-1-f243e4505b07@gmail.com


Signed-off-by: Lee Jones <lee@kernel.org>