iio: imu: inv-mpu6050: Fix interrupt pin configuration

The select/deselect_bypass duo writes the irq number into the interrupt
configuration register.
If there is a i2c slave device connected to the mpu (eg. a magnetometer)
then this can hinder interrupt delivery for the accelerometer and
gyroscope.
Set this register to the default configuration.

Signed-off-by: Adriana Reus <adriana.reus@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>