iio: imu: inv_mpu6050: delete not existing MPU9150 spi support

MPU9150 is i2c only.
Update Kconfig to delete in description chips that are i2c or
spi only.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>