iio: imu: st_lsm6dsx: Fix FIFO diff mask for tagged fifo

	According to the latest version of datasheet the mask
	for number of unread sensor data in FIFO_STATUS registers
	has been extended to 10 bits

	The devices involved are:
	 - LSM6DSO
	 - LSM6DSOX
	 - ASM330LHH
	 - LSM6DSR
	 - ISM330DHCX

Signed-off-by: mario tesi <mario.tesi@st.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>