media: i2c: video-i2c: Replace constants with proper names

Acc to MLX90640 datasheet:
 - 0x0400 represents the start of RAM address
 - 0x2400 represents the start of EEPROM address

Reference: https://www.melexis.com/-/media/files/documents\


           /datasheets/mlx90640-datasheet-melexis.pdf

Signed-off-by: Moses Christopher Bollavarapu <mosescb.dev@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>