board: am62x: Add support for reading eeprom data

board: am62x: Add support for reading eeprom data

I2C EEPROM data contains the board name and its revision.
Add support for:
- Reading EEPROM data and store a copy at end of SRAM
- Updating env variable with relevant board info
- Printing board info during boot

Use the generic do_board_detect_am6() and setup_serial_am6()
functions to avoid code duplication across AM6x family boards.

Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
Signed-off-by: Guillaume La Roque (TI.com) <glaroque@baylibre.com>