iio: imu: inv_mpu6050: fix objects syntax in Makefile

Use the correct syntax *-y for declaring object files.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/inv_mpu6050/Makefile

@@ -4,10 +4,10 @@
 #
 
 obj-$(CONFIG_INV_MPU6050_IIO) += inv-mpu6050.o
-inv-mpu6050-objs := inv_mpu_core.o inv_mpu_ring.o inv_mpu_trigger.o
+inv-mpu6050-y := inv_mpu_core.o inv_mpu_ring.o inv_mpu_trigger.o
 
 obj-$(CONFIG_INV_MPU6050_I2C) += inv-mpu6050-i2c.o
-inv-mpu6050-i2c-objs := inv_mpu_i2c.o inv_mpu_acpi.o
+inv-mpu6050-i2c-y := inv_mpu_i2c.o inv_mpu_acpi.o
 
 obj-$(CONFIG_INV_MPU6050_SPI) += inv-mpu6050-spi.o
-inv-mpu6050-spi-objs := inv_mpu_spi.o
+inv-mpu6050-spi-y := inv_mpu_spi.o