arm: mvebu: turris_omnia: Use the i2c_eeprom misc driver for EEPROM reading in U-Boot proper

Use the i2c_eeprom miscellaneous driver for reading Turris Omnia EEPROM
in U-Boot proper. Keep using dm_i2c_read() in SPL build, since adding
the i2c_eeprom driver to SPL build increases the image by 1.5 KiB.

Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>