platform/chrome: cros_ec_sensorhub: Allocate sensorhub resource before claiming sensors

platform/chrome: cros_ec_sensorhub: Allocate sensorhub resource before claiming sensors

Allocate callbacks array before enumerating the sensors: The probe routine
for these sensors (for instance cros_ec_sensors_probe) can be called
within the sensorhub probe routine (cros_ec_sensors_probe())

Fixes: 145d59baff594 ("platform/chrome: cros_ec_sensorhub: Add FIFO support")
Signed-off-by: Gwendal Grignou <[email protected]>
Reported-by: Douglas Anderson <[email protected]>
Tested-by: Douglas Anderson <[email protected]>
Signed-off-by: Enric Balletbo i Serra <[email protected]>