media: exynos4-is: fimc-is-i2c: remove I2C_CLASS_SPD support

This I2C bus is used by the firmware only and it seems I2C_CLASS_SPD
device auto-detection has never been used. So we can safely remove it.
That's one further step towards removing I2C_CLASS_SPD completely.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>