media: i2c: imx290: set the format before VIDIOC_SUBDEV_G_FMT is called
With the current driver 'media-ctl -p' issued right after the imx290 driver
is loaded prints:
pad0: Source
[fmt:unknown/0x0]
The format value of zero is due to the current_format field of the imx290
struct not being initialized yet.
As imx290_entity_init_cfg() calls imx290_set_fmt(), the current_mode field
is also initialized, so the line which set current_mode to a default value
in driver's probe() function is no longer needed.