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: e9e9d3973594 ("mfd: da9052: Avoid setting read_flag_mask for da9052-i2c driver")
Signed-off-by: Marcus Folkesson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/da9052-spi.c

···
 	spi_set_drvdata(spi, da9052);
 
 	config = da9052_regmap_config;
-	config.read_flag_mask = 1;
+	config.write_flag_mask = 1;
 	config.reg_bits = 7;
 	config.pad_bits = 1;
 	config.val_bits = 8;